diff --git a/src/ol/Graticule.js b/src/ol/Graticule.js
index 0fe38b2e58..6265ef2b2a 100644
--- a/src/ol/Graticule.js
+++ b/src/ol/Graticule.js
@@ -6,7 +6,7 @@ import {intersects, getCenter} from './extent.js';
 import GeometryLayout from './geom/GeometryLayout.js';
 import LineString from './geom/LineString.js';
 import Point from './geom/Point.js';
-import _ol_geom_flat_geodesic_ from './geom/flat/geodesic.js';
+import {meridian, parallel} from './geom/flat/geodesic.js';
 import {clamp} from './math.js';
 import {get as getProjection, equivalent as equivalentProjection, getTransform, transformExtent} from './proj.js';
 import RenderEventType from './render/EventType.js';
@@ -565,9 +565,8 @@ Graticule.prototype.getMap = function() {
  * @param {number} index Index.
  * @private
  */
-Graticule.prototype.getMeridian_ = function(lon, minLat, maxLat,
-  squaredTolerance, index) {
-  const flatCoordinates = _ol_geom_flat_geodesic_.meridian(lon,
+Graticule.prototype.getMeridian_ = function(lon, minLat, maxLat, squaredTolerance, index) {
+  const flatCoordinates = meridian(lon,
     minLat, maxLat, this.projection_, squaredTolerance);
   const lineString = this.meridians_[index] !== undefined ?
     this.meridians_[index] : new LineString(null);
@@ -595,9 +594,8 @@ Graticule.prototype.getMeridians = function() {
  * @param {number} index Index.
  * @private
  */
-Graticule.prototype.getParallel_ = function(lat, minLon, maxLon,
-  squaredTolerance, index) {
-  const flatCoordinates = _ol_geom_flat_geodesic_.parallel(lat,
+Graticule.prototype.getParallel_ = function(lat, minLon, maxLon, squaredTolerance, index) {
+  const flatCoordinates = parallel(lat,
     minLon, maxLon, this.projection_, squaredTolerance);
   const lineString = this.parallels_[index] !== undefined ?
     this.parallels_[index] : new LineString(null);
diff --git a/src/ol/format/Polyline.js b/src/ol/format/Polyline.js
index 8907f773e9..7177da7519 100644
--- a/src/ol/format/Polyline.js
+++ b/src/ol/format/Polyline.js
@@ -9,7 +9,7 @@ import TextFeature from '../format/TextFeature.js';
 import GeometryLayout from '../geom/GeometryLayout.js';
 import LineString from '../geom/LineString.js';
 import {getStrideForLayout} from '../geom/SimpleGeometry.js';
-import _ol_geom_flat_flip_ from '../geom/flat/flip.js';
+import {flipXY} from '../geom/flat/flip.js';
 import _ol_geom_flat_inflate_ from '../geom/flat/inflate.js';
 import {get as getProjection} from '../proj.js';
 
@@ -326,8 +326,7 @@ Polyline.prototype.readGeometry;
 Polyline.prototype.readGeometryFromText = function(text, opt_options) {
   const stride = getStrideForLayout(this.geometryLayout_);
   const flatCoordinates = decodeDeltas(text, stride, this.factor_);
-  _ol_geom_flat_flip_.flipXY(
-    flatCoordinates, 0, flatCoordinates.length, stride, flatCoordinates);
+  flipXY(flatCoordinates, 0, flatCoordinates.length, stride, flatCoordinates);
   const coordinates = _ol_geom_flat_inflate_.coordinates(
     flatCoordinates, 0, flatCoordinates.length, stride);
 
@@ -392,8 +391,7 @@ Polyline.prototype.writeGeometryText = function(geometry, opt_options) {
     (transformWithOptions(geometry, true, this.adaptOptions(opt_options)));
   const flatCoordinates = geometry.getFlatCoordinates();
   const stride = geometry.getStride();
-  _ol_geom_flat_flip_.flipXY(
-    flatCoordinates, 0, flatCoordinates.length, stride, flatCoordinates);
+  flipXY(flatCoordinates, 0, flatCoordinates.length, stride, flatCoordinates);
   return encodeDeltas(flatCoordinates, stride, this.factor_);
 };
 export default Polyline;
diff --git a/src/ol/geom/LineString.js b/src/ol/geom/LineString.js
index ba1fe244ef..010e5f1cb5 100644
--- a/src/ol/geom/LineString.js
+++ b/src/ol/geom/LineString.js
@@ -13,7 +13,7 @@ import _ol_geom_flat_inflate_ from '../geom/flat/inflate.js';
 import _ol_geom_flat_interpolate_ from '../geom/flat/interpolate.js';
 import _ol_geom_flat_intersectsextent_ from '../geom/flat/intersectsextent.js';
 import _ol_geom_flat_length_ from '../geom/flat/length.js';
-import _ol_geom_flat_segments_ from '../geom/flat/segments.js';
+import {forEach as forEachSegment} from '../geom/flat/segments.js';
 import _ol_geom_flat_simplify_ from '../geom/flat/simplify.js';
 
 /**
@@ -119,8 +119,7 @@ LineString.prototype.closestPointXY = function(x, y, closestPoint, minSquaredDis
  * @api
  */
 LineString.prototype.forEachSegment = function(callback) {
-  return _ol_geom_flat_segments_.forEach(this.flatCoordinates, 0,
-    this.flatCoordinates.length, this.stride, callback);
+  return forEachSegment(this.flatCoordinates, 0, this.flatCoordinates.length, this.stride, callback);
 };
 
 
diff --git a/src/ol/geom/LinearRing.js b/src/ol/geom/LinearRing.js
index ac3b354449..56b98bb9f2 100644
--- a/src/ol/geom/LinearRing.js
+++ b/src/ol/geom/LinearRing.js
@@ -6,7 +6,7 @@ import {closestSquaredDistanceXY} from '../extent.js';
 import GeometryLayout from '../geom/GeometryLayout.js';
 import GeometryType from '../geom/GeometryType.js';
 import SimpleGeometry from '../geom/SimpleGeometry.js';
-import _ol_geom_flat_area_ from '../geom/flat/area.js';
+import {linearRing as linearRingArea} from '../geom/flat/area.js';
 import _ol_geom_flat_closest_ from '../geom/flat/closest.js';
 import _ol_geom_flat_deflate_ from '../geom/flat/deflate.js';
 import _ol_geom_flat_inflate_ from '../geom/flat/inflate.js';
@@ -83,8 +83,7 @@ LinearRing.prototype.closestPointXY = function(x, y, closestPoint, minSquaredDis
  * @api
  */
 LinearRing.prototype.getArea = function() {
-  return _ol_geom_flat_area_.linearRing(
-    this.flatCoordinates, 0, this.flatCoordinates.length, this.stride);
+  return linearRingArea(this.flatCoordinates, 0, this.flatCoordinates.length, this.stride);
 };
 
 
diff --git a/src/ol/geom/MultiPolygon.js b/src/ol/geom/MultiPolygon.js
index f01b88d955..32132422ef 100644
--- a/src/ol/geom/MultiPolygon.js
+++ b/src/ol/geom/MultiPolygon.js
@@ -9,10 +9,10 @@ import GeometryType from '../geom/GeometryType.js';
 import MultiPoint from '../geom/MultiPoint.js';
 import Polygon from '../geom/Polygon.js';
 import SimpleGeometry from '../geom/SimpleGeometry.js';
-import _ol_geom_flat_area_ from '../geom/flat/area.js';
-import _ol_geom_flat_center_ from '../geom/flat/center.js';
+import {linearRingss as linearRingssArea} from '../geom/flat/area.js';
+import {linearRingss as linearRingssCenter} from '../geom/flat/center.js';
 import _ol_geom_flat_closest_ from '../geom/flat/closest.js';
-import _ol_geom_flat_contains_ from '../geom/flat/contains.js';
+import {linearRingssContainsXY} from '../geom/flat/contains.js';
 import _ol_geom_flat_deflate_ from '../geom/flat/deflate.js';
 import _ol_geom_flat_inflate_ from '../geom/flat/inflate.js';
 import _ol_geom_flat_interiorpoint_ from '../geom/flat/interiorpoint.js';
@@ -151,8 +151,7 @@ MultiPolygon.prototype.closestPointXY = function(x, y, closestPoint, minSquaredD
  * @inheritDoc
  */
 MultiPolygon.prototype.containsXY = function(x, y) {
-  return _ol_geom_flat_contains_.linearRingssContainsXY(
-    this.getOrientedFlatCoordinates(), 0, this.endss_, this.stride, x, y);
+  return linearRingssContainsXY(this.getOrientedFlatCoordinates(), 0, this.endss_, this.stride, x, y);
 };
 
 
@@ -162,8 +161,7 @@ MultiPolygon.prototype.containsXY = function(x, y) {
  * @api
  */
 MultiPolygon.prototype.getArea = function() {
-  return _ol_geom_flat_area_.linearRingss(
-    this.getOrientedFlatCoordinates(), 0, this.endss_, this.stride);
+  return linearRingssArea(this.getOrientedFlatCoordinates(), 0, this.endss_, this.stride);
 };
 
 
@@ -209,7 +207,7 @@ MultiPolygon.prototype.getEndss = function() {
  */
 MultiPolygon.prototype.getFlatInteriorPoints = function() {
   if (this.flatInteriorPointsRevision_ != this.getRevision()) {
-    const flatCenters = _ol_geom_flat_center_.linearRingss(
+    const flatCenters = linearRingssCenter(
       this.flatCoordinates, 0, this.endss_, this.stride);
     this.flatInteriorPoints_ = _ol_geom_flat_interiorpoint_.linearRingss(
       this.getOrientedFlatCoordinates(), 0, this.endss_, this.stride,
diff --git a/src/ol/geom/Polygon.js b/src/ol/geom/Polygon.js
index 47cddbf8c5..388b5ec39b 100644
--- a/src/ol/geom/Polygon.js
+++ b/src/ol/geom/Polygon.js
@@ -10,9 +10,9 @@ import LinearRing from '../geom/LinearRing.js';
 import Point from '../geom/Point.js';
 import SimpleGeometry from '../geom/SimpleGeometry.js';
 import {offset as sphereOffset} from '../sphere.js';
-import _ol_geom_flat_area_ from '../geom/flat/area.js';
+import {linearRings as linearRingsArea} from '../geom/flat/area.js';
 import _ol_geom_flat_closest_ from '../geom/flat/closest.js';
-import _ol_geom_flat_contains_ from '../geom/flat/contains.js';
+import {linearRingsContainsXY} from '../geom/flat/contains.js';
 import _ol_geom_flat_deflate_ from '../geom/flat/deflate.js';
 import _ol_geom_flat_inflate_ from '../geom/flat/inflate.js';
 import _ol_geom_flat_interiorpoint_ from '../geom/flat/interiorpoint.js';
@@ -141,8 +141,7 @@ Polygon.prototype.closestPointXY = function(x, y, closestPoint, minSquaredDistan
  * @inheritDoc
  */
 Polygon.prototype.containsXY = function(x, y) {
-  return _ol_geom_flat_contains_.linearRingsContainsXY(
-    this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride, x, y);
+  return linearRingsContainsXY(this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride, x, y);
 };
 
 
@@ -152,8 +151,7 @@ Polygon.prototype.containsXY = function(x, y) {
  * @api
  */
 Polygon.prototype.getArea = function() {
-  return _ol_geom_flat_area_.linearRings(
-    this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride);
+  return linearRingsArea(this.getOrientedFlatCoordinates(), 0, this.ends_, this.stride);
 };
 
 
diff --git a/src/ol/geom/flat/area.js b/src/ol/geom/flat/area.js
index 6188d58524..b9de7021c5 100644
--- a/src/ol/geom/flat/area.js
+++ b/src/ol/geom/flat/area.js
@@ -1,7 +1,6 @@
 /**
  * @module ol/geom/flat/area
  */
-const _ol_geom_flat_area_ = {};
 
 
 /**
@@ -11,7 +10,7 @@ const _ol_geom_flat_area_ = {};
  * @param {number} stride Stride.
  * @return {number} Area.
  */
-_ol_geom_flat_area_.linearRing = function(flatCoordinates, offset, end, stride) {
+export function linearRing(flatCoordinates, offset, end, stride) {
   let twiceArea = 0;
   let x1 = flatCoordinates[end - stride];
   let y1 = flatCoordinates[end - stride + 1];
@@ -23,7 +22,7 @@ _ol_geom_flat_area_.linearRing = function(flatCoordinates, offset, end, stride)
     y1 = y2;
   }
   return twiceArea / 2;
-};
+}
 
 
 /**
@@ -33,15 +32,15 @@ _ol_geom_flat_area_.linearRing = function(flatCoordinates, offset, end, stride)
  * @param {number} stride Stride.
  * @return {number} Area.
  */
-_ol_geom_flat_area_.linearRings = function(flatCoordinates, offset, ends, stride) {
+export function linearRings(flatCoordinates, offset, ends, stride) {
   let area = 0;
   for (let i = 0, ii = ends.length; i < ii; ++i) {
     const end = ends[i];
-    area += _ol_geom_flat_area_.linearRing(flatCoordinates, offset, end, stride);
+    area += linearRing(flatCoordinates, offset, end, stride);
     offset = end;
   }
   return area;
-};
+}
 
 
 /**
@@ -51,13 +50,12 @@ _ol_geom_flat_area_.linearRings = function(flatCoordinates, offset, ends, stride
  * @param {number} stride Stride.
  * @return {number} Area.
  */
-_ol_geom_flat_area_.linearRingss = function(flatCoordinates, offset, endss, stride) {
+export function linearRingss(flatCoordinates, offset, endss, stride) {
   let area = 0;
   for (let i = 0, ii = endss.length; i < ii; ++i) {
     const ends = endss[i];
-    area += _ol_geom_flat_area_.linearRings(flatCoordinates, offset, ends, stride);
+    area += linearRings(flatCoordinates, offset, ends, stride);
     offset = ends[ends.length - 1];
   }
   return area;
-};
-export default _ol_geom_flat_area_;
+}
diff --git a/src/ol/geom/flat/center.js b/src/ol/geom/flat/center.js
index 27887f37d5..2e5b6519f2 100644
--- a/src/ol/geom/flat/center.js
+++ b/src/ol/geom/flat/center.js
@@ -2,7 +2,6 @@
  * @module ol/geom/flat/center
  */
 import {createEmpty, createOrUpdateFromFlatCoordinates} from '../../extent.js';
-const _ol_geom_flat_center_ = {};
 
 
 /**
@@ -12,7 +11,7 @@ const _ol_geom_flat_center_ = {};
  * @param {number} stride Stride.
  * @return {Array.<number>} Flat centers.
  */
-_ol_geom_flat_center_.linearRingss = function(flatCoordinates, offset, endss, stride) {
+export function linearRingss(flatCoordinates, offset, endss, stride) {
   const flatCenters = [];
   let extent = createEmpty();
   for (let i = 0, ii = endss.length; i < ii; ++i) {
@@ -22,5 +21,4 @@ _ol_geom_flat_center_.linearRingss = function(flatCoordinates, offset, endss, st
     offset = ends[ends.length - 1];
   }
   return flatCenters;
-};
-export default _ol_geom_flat_center_;
+}
diff --git a/src/ol/geom/flat/contains.js b/src/ol/geom/flat/contains.js
index cd4c54bf8b..acc843e992 100644
--- a/src/ol/geom/flat/contains.js
+++ b/src/ol/geom/flat/contains.js
@@ -2,7 +2,6 @@
  * @module ol/geom/flat/contains
  */
 import {forEachCorner} from '../../extent.js';
-const _ol_geom_flat_contains_ = {};
 
 
 /**
@@ -13,18 +12,17 @@ const _ol_geom_flat_contains_ = {};
  * @param {ol.Extent} extent Extent.
  * @return {boolean} Contains extent.
  */
-_ol_geom_flat_contains_.linearRingContainsExtent = function(flatCoordinates, offset, end, stride, extent) {
+export function linearRingContainsExtent(flatCoordinates, offset, end, stride, extent) {
   const outside = forEachCorner(extent,
     /**
-       * @param {ol.Coordinate} coordinate Coordinate.
-       * @return {boolean} Contains (x, y).
-       */
+     * @param {ol.Coordinate} coordinate Coordinate.
+     * @return {boolean} Contains (x, y).
+     */
     function(coordinate) {
-      return !_ol_geom_flat_contains_.linearRingContainsXY(flatCoordinates,
-        offset, end, stride, coordinate[0], coordinate[1]);
+      return !linearRingContainsXY(flatCoordinates, offset, end, stride, coordinate[0], coordinate[1]);
     });
   return !outside;
-};
+}
 
 
 /**
@@ -36,7 +34,7 @@ _ol_geom_flat_contains_.linearRingContainsExtent = function(flatCoordinates, off
  * @param {number} y Y.
  * @return {boolean} Contains (x, y).
  */
-_ol_geom_flat_contains_.linearRingContainsXY = function(flatCoordinates, offset, end, stride, x, y) {
+export function linearRingContainsXY(flatCoordinates, offset, end, stride, x, y) {
   // http://geomalgorithms.com/a03-_inclusion.html
   // Copyright 2000 softSurfer, 2012 Dan Sunday
   // This code may be freely used and modified for any purpose
@@ -61,7 +59,7 @@ _ol_geom_flat_contains_.linearRingContainsXY = function(flatCoordinates, offset,
     y1 = y2;
   }
   return wn !== 0;
-};
+}
 
 
 /**
@@ -73,22 +71,20 @@ _ol_geom_flat_contains_.linearRingContainsXY = function(flatCoordinates, offset,
  * @param {number} y Y.
  * @return {boolean} Contains (x, y).
  */
-_ol_geom_flat_contains_.linearRingsContainsXY = function(flatCoordinates, offset, ends, stride, x, y) {
+export function linearRingsContainsXY(flatCoordinates, offset, ends, stride, x, y) {
   if (ends.length === 0) {
     return false;
   }
-  if (!_ol_geom_flat_contains_.linearRingContainsXY(
-    flatCoordinates, offset, ends[0], stride, x, y)) {
+  if (!linearRingContainsXY(flatCoordinates, offset, ends[0], stride, x, y)) {
     return false;
   }
   for (let i = 1, ii = ends.length; i < ii; ++i) {
-    if (_ol_geom_flat_contains_.linearRingContainsXY(
-      flatCoordinates, ends[i - 1], ends[i], stride, x, y)) {
+    if (linearRingContainsXY(flatCoordinates, ends[i - 1], ends[i], stride, x, y)) {
       return false;
     }
   }
   return true;
-};
+}
 
 
 /**
@@ -100,18 +96,16 @@ _ol_geom_flat_contains_.linearRingsContainsXY = function(flatCoordinates, offset
  * @param {number} y Y.
  * @return {boolean} Contains (x, y).
  */
-_ol_geom_flat_contains_.linearRingssContainsXY = function(flatCoordinates, offset, endss, stride, x, y) {
+export function linearRingssContainsXY(flatCoordinates, offset, endss, stride, x, y) {
   if (endss.length === 0) {
     return false;
   }
   for (let i = 0, ii = endss.length; i < ii; ++i) {
     const ends = endss[i];
-    if (_ol_geom_flat_contains_.linearRingsContainsXY(
-      flatCoordinates, offset, ends, stride, x, y)) {
+    if (linearRingsContainsXY(flatCoordinates, offset, ends, stride, x, y)) {
       return true;
     }
     offset = ends[ends.length - 1];
   }
   return false;
-};
-export default _ol_geom_flat_contains_;
+}
diff --git a/src/ol/geom/flat/flip.js b/src/ol/geom/flat/flip.js
index 53658ca0e0..4e434a892a 100644
--- a/src/ol/geom/flat/flip.js
+++ b/src/ol/geom/flat/flip.js
@@ -1,7 +1,6 @@
 /**
  * @module ol/geom/flat/flip
  */
-const _ol_geom_flat_flip_ = {};
 
 
 /**
@@ -13,7 +12,7 @@ const _ol_geom_flat_flip_ = {};
  * @param {number=} opt_destOffset Destination offset.
  * @return {Array.<number>} Flat coordinates.
  */
-_ol_geom_flat_flip_.flipXY = function(flatCoordinates, offset, end, stride, opt_dest, opt_destOffset) {
+export function flipXY(flatCoordinates, offset, end, stride, opt_dest, opt_destOffset) {
   let dest, destOffset;
   if (opt_dest !== undefined) {
     dest = opt_dest;
@@ -33,5 +32,4 @@ _ol_geom_flat_flip_.flipXY = function(flatCoordinates, offset, end, stride, opt_
   }
   dest.length = destOffset;
   return dest;
-};
-export default _ol_geom_flat_flip_;
+}
diff --git a/src/ol/geom/flat/geodesic.js b/src/ol/geom/flat/geodesic.js
index dfaeabedcf..3b6c5c0dee 100644
--- a/src/ol/geom/flat/geodesic.js
+++ b/src/ol/geom/flat/geodesic.js
@@ -3,18 +3,16 @@
  */
 import {squaredSegmentDistance, toRadians, toDegrees} from '../../math.js';
 import {get as getProjection, getTransform} from '../../proj.js';
-const _ol_geom_flat_geodesic_ = {};
 
 
 /**
- * @private
  * @param {function(number): ol.Coordinate} interpolate Interpolate function.
  * @param {ol.TransformFunction} transform Transform from longitude/latitude to
  *     projected coordinates.
  * @param {number} squaredTolerance Squared tolerance.
  * @return {Array.<number>} Flat coordinates.
  */
-_ol_geom_flat_geodesic_.line_ = function(interpolate, transform, squaredTolerance) {
+function line(interpolate, transform, squaredTolerance) {
   // FIXME reduce garbage generation
   // FIXME optimize stack operations
 
@@ -77,22 +75,20 @@ _ol_geom_flat_geodesic_.line_ = function(interpolate, transform, squaredToleranc
   }
 
   return flatCoordinates;
-};
+}
 
 
 /**
-* Generate a great-circle arcs between two lat/lon points.
-* @param {number} lon1 Longitude 1 in degrees.
-* @param {number} lat1 Latitude 1 in degrees.
-* @param {number} lon2 Longitude 2 in degrees.
-* @param {number} lat2 Latitude 2 in degrees.
+ * Generate a great-circle arcs between two lat/lon points.
+ * @param {number} lon1 Longitude 1 in degrees.
+ * @param {number} lat1 Latitude 1 in degrees.
+ * @param {number} lon2 Longitude 2 in degrees.
+ * @param {number} lat2 Latitude 2 in degrees.
  * @param {ol.proj.Projection} projection Projection.
-* @param {number} squaredTolerance Squared tolerance.
-* @return {Array.<number>} Flat coordinates.
-*/
-_ol_geom_flat_geodesic_.greatCircleArc = function(
-  lon1, lat1, lon2, lat2, projection, squaredTolerance) {
-
+ * @param {number} squaredTolerance Squared tolerance.
+ * @return {Array.<number>} Flat coordinates.
+ */
+export function greatCircleArc(lon1, lat1, lon2, lat2, projection, squaredTolerance) {
   const geoProjection = getProjection('EPSG:4326');
 
   const cosLat1 = Math.cos(toRadians(lat1));
@@ -103,11 +99,11 @@ _ol_geom_flat_geodesic_.greatCircleArc = function(
   const sinDeltaLon = Math.sin(toRadians(lon2 - lon1));
   const d = sinLat1 * sinLat2 + cosLat1 * cosLat2 * cosDeltaLon;
 
-  return _ol_geom_flat_geodesic_.line_(
+  return line(
     /**
-       * @param {number} frac Fraction.
-       * @return {ol.Coordinate} Coordinate.
-       */
+     * @param {number} frac Fraction.
+     * @return {ol.Coordinate} Coordinate.
+     */
     function(frac) {
       if (1 <= d) {
         return [lon2, lat2];
@@ -124,7 +120,7 @@ _ol_geom_flat_geodesic_.greatCircleArc = function(
               cosD - sinLat1 * Math.sin(lat));
       return [toDegrees(lon), toDegrees(lat)];
     }, getTransform(geoProjection, projection), squaredTolerance);
-};
+}
 
 
 /**
@@ -136,18 +132,18 @@ _ol_geom_flat_geodesic_.greatCircleArc = function(
  * @param {number} squaredTolerance Squared tolerance.
  * @return {Array.<number>} Flat coordinates.
  */
-_ol_geom_flat_geodesic_.meridian = function(lon, lat1, lat2, projection, squaredTolerance) {
+export function meridian(lon, lat1, lat2, projection, squaredTolerance) {
   const epsg4326Projection = getProjection('EPSG:4326');
-  return _ol_geom_flat_geodesic_.line_(
+  return line(
     /**
-       * @param {number} frac Fraction.
-       * @return {ol.Coordinate} Coordinate.
-       */
+     * @param {number} frac Fraction.
+     * @return {ol.Coordinate} Coordinate.
+     */
     function(frac) {
       return [lon, lat1 + ((lat2 - lat1) * frac)];
     },
     getTransform(epsg4326Projection, projection), squaredTolerance);
-};
+}
 
 
 /**
@@ -159,16 +155,15 @@ _ol_geom_flat_geodesic_.meridian = function(lon, lat1, lat2, projection, squared
  * @param {number} squaredTolerance Squared tolerance.
  * @return {Array.<number>} Flat coordinates.
  */
-_ol_geom_flat_geodesic_.parallel = function(lat, lon1, lon2, projection, squaredTolerance) {
+export function parallel(lat, lon1, lon2, projection, squaredTolerance) {
   const epsg4326Projection = getProjection('EPSG:4326');
-  return _ol_geom_flat_geodesic_.line_(
+  return line(
     /**
-       * @param {number} frac Fraction.
-       * @return {ol.Coordinate} Coordinate.
-       */
+     * @param {number} frac Fraction.
+     * @return {ol.Coordinate} Coordinate.
+     */
     function(frac) {
       return [lon1 + ((lon2 - lon1) * frac), lat];
     },
     getTransform(epsg4326Projection, projection), squaredTolerance);
-};
-export default _ol_geom_flat_geodesic_;
+}
diff --git a/src/ol/geom/flat/interiorpoint.js b/src/ol/geom/flat/interiorpoint.js
index 1c189648f9..8045d4980a 100644
--- a/src/ol/geom/flat/interiorpoint.js
+++ b/src/ol/geom/flat/interiorpoint.js
@@ -2,7 +2,7 @@
  * @module ol/geom/flat/interiorpoint
  */
 import {numberSafeCompareFunction} from '../../array.js';
-import _ol_geom_flat_contains_ from '../flat/contains.js';
+import {linearRingsContainsXY} from '../flat/contains.js';
 const _ol_geom_flat_interiorpoint_ = {};
 
 
@@ -52,8 +52,7 @@ _ol_geom_flat_interiorpoint_.linearRings = function(flatCoordinates, offset,
     const segmentLength = Math.abs(x2 - x1);
     if (segmentLength > maxSegmentLength) {
       x = (x1 + x2) / 2;
-      if (_ol_geom_flat_contains_.linearRingsContainsXY(
-        flatCoordinates, offset, ends, stride, x, y)) {
+      if (linearRingsContainsXY(flatCoordinates, offset, ends, stride, x, y)) {
         pointX = x;
         maxSegmentLength = segmentLength;
       }
diff --git a/src/ol/geom/flat/intersectsextent.js b/src/ol/geom/flat/intersectsextent.js
index 911743f282..e4dfb1f200 100644
--- a/src/ol/geom/flat/intersectsextent.js
+++ b/src/ol/geom/flat/intersectsextent.js
@@ -2,8 +2,8 @@
  * @module ol/geom/flat/intersectsextent
  */
 import {containsExtent, createEmpty, extendFlatCoordinates, intersects, intersectsSegment} from '../../extent.js';
-import _ol_geom_flat_contains_ from '../flat/contains.js';
-import _ol_geom_flat_segments_ from '../flat/segments.js';
+import {linearRingContainsXY, linearRingContainsExtent} from '../flat/contains.js';
+import {forEach as forEachSegment} from '../flat/segments.js';
 const _ol_geom_flat_intersectsextent_ = {};
 
 
@@ -32,13 +32,13 @@ _ol_geom_flat_intersectsextent_.lineString = function(flatCoordinates, offset, e
       coordinatesExtent[3] <= extent[3]) {
     return true;
   }
-  return _ol_geom_flat_segments_.forEach(flatCoordinates, offset, end, stride,
+  return forEachSegment(flatCoordinates, offset, end, stride,
     /**
-       * @param {ol.Coordinate} point1 Start point.
-       * @param {ol.Coordinate} point2 End point.
-       * @return {boolean} `true` if the segment and the extent intersect,
-       *     `false` otherwise.
-       */
+     * @param {ol.Coordinate} point1 Start point.
+     * @param {ol.Coordinate} point2 End point.
+     * @return {boolean} `true` if the segment and the extent intersect,
+     *     `false` otherwise.
+     */
     function(point1, point2) {
       return intersectsSegment(extent, point1, point2);
     });
@@ -78,20 +78,16 @@ _ol_geom_flat_intersectsextent_.linearRing = function(flatCoordinates, offset, e
     flatCoordinates, offset, end, stride, extent)) {
     return true;
   }
-  if (_ol_geom_flat_contains_.linearRingContainsXY(
-    flatCoordinates, offset, end, stride, extent[0], extent[1])) {
+  if (linearRingContainsXY(flatCoordinates, offset, end, stride, extent[0], extent[1])) {
     return true;
   }
-  if (_ol_geom_flat_contains_.linearRingContainsXY(
-    flatCoordinates, offset, end, stride, extent[0], extent[3])) {
+  if (linearRingContainsXY(flatCoordinates, offset, end, stride, extent[0], extent[3])) {
     return true;
   }
-  if (_ol_geom_flat_contains_.linearRingContainsXY(
-    flatCoordinates, offset, end, stride, extent[2], extent[1])) {
+  if (linearRingContainsXY(flatCoordinates, offset, end, stride, extent[2], extent[1])) {
     return true;
   }
-  if (_ol_geom_flat_contains_.linearRingContainsXY(
-    flatCoordinates, offset, end, stride, extent[2], extent[3])) {
+  if (linearRingContainsXY(flatCoordinates, offset, end, stride, extent[2], extent[3])) {
     return true;
   }
   return false;
@@ -115,8 +111,7 @@ _ol_geom_flat_intersectsextent_.linearRings = function(flatCoordinates, offset,
     return true;
   }
   for (let i = 1, ii = ends.length; i < ii; ++i) {
-    if (_ol_geom_flat_contains_.linearRingContainsExtent(
-      flatCoordinates, ends[i - 1], ends[i], stride, extent)) {
+    if (linearRingContainsExtent(flatCoordinates, ends[i - 1], ends[i], stride, extent)) {
       return false;
     }
   }
diff --git a/src/ol/geom/flat/orient.js b/src/ol/geom/flat/orient.js
index 60d449ec2c..ef0467880a 100644
--- a/src/ol/geom/flat/orient.js
+++ b/src/ol/geom/flat/orient.js
@@ -1,7 +1,7 @@
 /**
  * @module ol/geom/flat/orient
  */
-import _ol_geom_flat_reverse_ from '../flat/reverse.js';
+import {coordinates as reverseCoordinates} from '../flat/reverse.js';
 const _ol_geom_flat_orient_ = {};
 
 
@@ -110,7 +110,7 @@ _ol_geom_flat_orient_.orientLinearRings = function(flatCoordinates, offset, ends
       (right && isClockwise) || (!right && !isClockwise) :
       (right && !isClockwise) || (!right && isClockwise);
     if (reverse) {
-      _ol_geom_flat_reverse_.coordinates(flatCoordinates, offset, end, stride);
+      reverseCoordinates(flatCoordinates, offset, end, stride);
     }
     offset = end;
   }
diff --git a/src/ol/geom/flat/reverse.js b/src/ol/geom/flat/reverse.js
index e04d450d3f..bdb1e0c041 100644
--- a/src/ol/geom/flat/reverse.js
+++ b/src/ol/geom/flat/reverse.js
@@ -1,7 +1,6 @@
 /**
  * @module ol/geom/flat/reverse
  */
-const _ol_geom_flat_reverse_ = {};
 
 
 /**
@@ -10,7 +9,7 @@ const _ol_geom_flat_reverse_ = {};
  * @param {number} end End.
  * @param {number} stride Stride.
  */
-_ol_geom_flat_reverse_.coordinates = function(flatCoordinates, offset, end, stride) {
+export function coordinates(flatCoordinates, offset, end, stride) {
   while (offset < end - stride) {
     for (let i = 0; i < stride; ++i) {
       const tmp = flatCoordinates[offset + i];
@@ -20,5 +19,4 @@ _ol_geom_flat_reverse_.coordinates = function(flatCoordinates, offset, end, stri
     offset += stride;
     end -= stride;
   }
-};
-export default _ol_geom_flat_reverse_;
+}
diff --git a/src/ol/geom/flat/segments.js b/src/ol/geom/flat/segments.js
index d97150bee0..c7cb402ced 100644
--- a/src/ol/geom/flat/segments.js
+++ b/src/ol/geom/flat/segments.js
@@ -1,7 +1,6 @@
 /**
  * @module ol/geom/flat/segments
  */
-const _ol_geom_flat_segments_ = {};
 
 
 /**
@@ -19,7 +18,7 @@ const _ol_geom_flat_segments_ = {};
  * @return {T|boolean} Value.
  * @template T,S
  */
-_ol_geom_flat_segments_.forEach = function(flatCoordinates, offset, end, stride, callback, opt_this) {
+export function forEach(flatCoordinates, offset, end, stride, callback, opt_this) {
   const point1 = [flatCoordinates[offset], flatCoordinates[offset + 1]];
   const point2 = [];
   let ret;
@@ -34,5 +33,4 @@ _ol_geom_flat_segments_.forEach = function(flatCoordinates, offset, end, stride,
     point1[1] = point2[1];
   }
   return false;
-};
-export default _ol_geom_flat_segments_;
+}
diff --git a/src/ol/geom/flat/topology.js b/src/ol/geom/flat/topology.js
index 2bd605b88e..e594c975f0 100644
--- a/src/ol/geom/flat/topology.js
+++ b/src/ol/geom/flat/topology.js
@@ -1,8 +1,7 @@
 /**
  * @module ol/geom/flat/topology
  */
-import _ol_geom_flat_area_ from '../flat/area.js';
-const _ol_geom_flat_topology_ = {};
+import {linearRing as linearRingArea} from '../flat/area.js';
 
 /**
  * Check if the linestring is a boundary.
@@ -12,12 +11,11 @@ const _ol_geom_flat_topology_ = {};
  * @param {number} stride Stride.
  * @return {boolean} The linestring is a boundary.
  */
-_ol_geom_flat_topology_.lineStringIsClosed = function(flatCoordinates, offset, end, stride) {
+export function lineStringIsClosed(flatCoordinates, offset, end, stride) {
   const lastCoord = end - stride;
   if (flatCoordinates[offset] === flatCoordinates[lastCoord] &&
       flatCoordinates[offset + 1] === flatCoordinates[lastCoord + 1] && (end - offset) / stride > 3) {
-    return !!_ol_geom_flat_area_.linearRing(flatCoordinates, offset, end, stride);
+    return !!linearRingArea(flatCoordinates, offset, end, stride);
   }
   return false;
-};
-export default _ol_geom_flat_topology_;
+}
diff --git a/src/ol/interaction/KeyboardPan.js b/src/ol/interaction/KeyboardPan.js
index b3cb67e99a..41d7b28166 100644
--- a/src/ol/interaction/KeyboardPan.js
+++ b/src/ol/interaction/KeyboardPan.js
@@ -4,7 +4,7 @@
 import {inherits} from '../index.js';
 import _ol_coordinate_ from '../coordinate.js';
 import EventType from '../events/EventType.js';
-import _ol_events_KeyCode_ from '../events/KeyCode.js';
+import KeyCode from '../events/KeyCode.js';
 import _ol_events_condition_ from '../events/condition.js';
 import Interaction from '../interaction/Interaction.js';
 
@@ -82,19 +82,19 @@ KeyboardPan.handleEvent = function(mapBrowserEvent) {
     const keyEvent = mapBrowserEvent.originalEvent;
     const keyCode = keyEvent.keyCode;
     if (this.condition_(mapBrowserEvent) &&
-        (keyCode == _ol_events_KeyCode_.DOWN ||
-        keyCode == _ol_events_KeyCode_.LEFT ||
-        keyCode == _ol_events_KeyCode_.RIGHT ||
-        keyCode == _ol_events_KeyCode_.UP)) {
+        (keyCode == KeyCode.DOWN ||
+        keyCode == KeyCode.LEFT ||
+        keyCode == KeyCode.RIGHT ||
+        keyCode == KeyCode.UP)) {
       const map = mapBrowserEvent.map;
       const view = map.getView();
       const mapUnitsDelta = view.getResolution() * this.pixelDelta_;
       let deltaX = 0, deltaY = 0;
-      if (keyCode == _ol_events_KeyCode_.DOWN) {
+      if (keyCode == KeyCode.DOWN) {
         deltaY = -mapUnitsDelta;
-      } else if (keyCode == _ol_events_KeyCode_.LEFT) {
+      } else if (keyCode == KeyCode.LEFT) {
         deltaX = -mapUnitsDelta;
-      } else if (keyCode == _ol_events_KeyCode_.RIGHT) {
+      } else if (keyCode == KeyCode.RIGHT) {
         deltaX = mapUnitsDelta;
       } else {
         deltaY = mapUnitsDelta;
diff --git a/src/ol/render/Feature.js b/src/ol/render/Feature.js
index 8731d7455f..369c65442c 100644
--- a/src/ol/render/Feature.js
+++ b/src/ol/render/Feature.js
@@ -5,7 +5,7 @@ import {nullFunction} from '../index.js';
 import {extend} from '../array.js';
 import {createOrUpdateFromCoordinate, createOrUpdateFromFlatCoordinates, getCenter, getHeight} from '../extent.js';
 import GeometryType from '../geom/GeometryType.js';
-import _ol_geom_flat_center_ from '../geom/flat/center.js';
+import {linearRingss as linearRingssCenter} from '../geom/flat/center.js';
 import _ol_geom_flat_interiorpoint_ from '../geom/flat/interiorpoint.js';
 import _ol_geom_flat_interpolate_ from '../geom/flat/interpolate.js';
 import _ol_geom_flat_transform_ from '../geom/flat/transform.js';
@@ -137,7 +137,7 @@ RenderFeature.prototype.getFlatInteriorPoint = function() {
  */
 RenderFeature.prototype.getFlatInteriorPoints = function() {
   if (!this.flatInteriorPoints_) {
-    const flatCenters = _ol_geom_flat_center_.linearRingss(
+    const flatCenters = linearRingssCenter(
       this.flatCoordinates_, 0, this.ends_, 2);
     this.flatInteriorPoints_ = _ol_geom_flat_interiorpoint_.linearRingss(
       this.flatCoordinates_, 0, this.ends_, 2, flatCenters);
diff --git a/src/ol/render/webgl/LineStringReplay.js b/src/ol/render/webgl/LineStringReplay.js
index e0d2dbabd7..ccdf19a898 100644
--- a/src/ol/render/webgl/LineStringReplay.js
+++ b/src/ol/render/webgl/LineStringReplay.js
@@ -7,7 +7,7 @@ import {asArray} from '../../color.js';
 import {intersects} from '../../extent.js';
 import _ol_geom_flat_orient_ from '../../geom/flat/orient.js';
 import _ol_geom_flat_transform_ from '../../geom/flat/transform.js';
-import _ol_geom_flat_topology_ from '../../geom/flat/topology.js';
+import {lineStringIsClosed} from '../../geom/flat/topology.js';
 import {isEmpty} from '../../obj.js';
 import _ol_render_webgl_ from '../webgl.js';
 import WebGLReplay from '../webgl/Replay.js';
@@ -91,7 +91,7 @@ WebGLLineStringReplay.prototype.drawCoordinates_ = function(flatCoordinates, off
     this.state_.lineJoin === 'miter' ? 1 : 2;
   const lineCap = this.state_.lineCap === 'butt' ? 0 :
     this.state_.lineCap === 'square' ? 1 : 2;
-  const closed = _ol_geom_flat_topology_.lineStringIsClosed(flatCoordinates, offset, end, stride);
+  const closed = lineStringIsClosed(flatCoordinates, offset, end, stride);
   let startCoords, sign, n;
   let lastIndex = numIndices;
   let lastSign = 1;
@@ -357,8 +357,7 @@ WebGLLineStringReplay.prototype.drawMultiLineString = function(multiLineStringGe
  */
 WebGLLineStringReplay.prototype.drawPolygonCoordinates = function(
   flatCoordinates, holeFlatCoordinates, stride) {
-  if (!_ol_geom_flat_topology_.lineStringIsClosed(flatCoordinates, 0,
-    flatCoordinates.length, stride)) {
+  if (!lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, stride)) {
     flatCoordinates.push(flatCoordinates[0]);
     flatCoordinates.push(flatCoordinates[1]);
   }
@@ -366,8 +365,7 @@ WebGLLineStringReplay.prototype.drawPolygonCoordinates = function(
   if (holeFlatCoordinates.length) {
     let i, ii;
     for (i = 0, ii = holeFlatCoordinates.length; i < ii; ++i) {
-      if (!_ol_geom_flat_topology_.lineStringIsClosed(holeFlatCoordinates[i], 0,
-        holeFlatCoordinates[i].length, stride)) {
+      if (!lineStringIsClosed(holeFlatCoordinates[i], 0, holeFlatCoordinates[i].length, stride)) {
         holeFlatCoordinates[i].push(holeFlatCoordinates[i][0]);
         holeFlatCoordinates[i].push(holeFlatCoordinates[i][1]);
       }
diff --git a/src/ol/render/webgl/PolygonReplay.js b/src/ol/render/webgl/PolygonReplay.js
index dabce0cb48..433ae5634c 100644
--- a/src/ol/render/webgl/PolygonReplay.js
+++ b/src/ol/render/webgl/PolygonReplay.js
@@ -6,7 +6,7 @@ import {equals} from '../../array.js';
 import {asArray} from '../../color.js';
 import {intersects} from '../../extent.js';
 import {isEmpty} from '../../obj.js';
-import _ol_geom_flat_contains_ from '../../geom/flat/contains.js';
+import {linearRingContainsXY} from '../../geom/flat/contains.js';
 import _ol_geom_flat_orient_ from '../../geom/flat/orient.js';
 import _ol_geom_flat_transform_ from '../../geom/flat/transform.js';
 import _ol_render_webgl_polygonreplay_defaultshader_ from '../webgl/polygonreplay/defaultshader.js';
@@ -663,8 +663,7 @@ WebGLPolygonReplay.prototype.getPointsInTriangle_ = function(p0, p1, p2, rtree,
       if (typeof p === 'object' && (!opt_reflex || p.reflex)) {
         if ((p.x !== p0.x || p.y !== p0.y) && (p.x !== p1.x || p.y !== p1.y) &&
             (p.x !== p2.x || p.y !== p2.y) && result.indexOf(p) === -1 &&
-            _ol_geom_flat_contains_.linearRingContainsXY([p0.x, p0.y, p1.x, p1.y,
-              p2.x, p2.y], 0, 6, 2, p.x, p.y)) {
+            linearRingContainsXY([p0.x, p0.y, p1.x, p1.y, p2.x, p2.y], 0, 6, 2, p.x, p.y)) {
           result.push(p);
         }
       }
diff --git a/test/spec/ol/geom/flat/area.test.js b/test/spec/ol/geom/flat/area.test.js
index 4590c81c78..bbf7a747ea 100644
--- a/test/spec/ol/geom/flat/area.test.js
+++ b/test/spec/ol/geom/flat/area.test.js
@@ -1,17 +1,16 @@
-import _ol_geom_flat_area_ from '../../../../../src/ol/geom/flat/area.js';
+import {linearRing, linearRings} from '../../../../../src/ol/geom/flat/area.js';
 
 describe('ol.geom.flat.area', function() {
 
   describe('ol.geom.flat.area.linearRing', function() {
 
     it('calculates the area of a triangle', function() {
-      const area = _ol_geom_flat_area_.linearRing([0, 0, 0.5, 1, 1, 0], 0, 6, 2);
+      const area = linearRing([0, 0, 0.5, 1, 1, 0], 0, 6, 2);
       expect(area).to.be(0.5);
     });
 
     it('calculates the area of a unit square', function() {
-      const area =
-          _ol_geom_flat_area_.linearRing([0, 0, 0, 1, 1, 1, 1, 0], 0, 8, 2);
+      const area = linearRing([0, 0, 0, 1, 1, 1, 1, 0], 0, 8, 2);
       expect(area).to.be(1);
     });
 
@@ -20,7 +19,7 @@ describe('ol.geom.flat.area', function() {
   describe('ol.geom.flat.area.linearRings', function() {
 
     it('calculates the area with holes', function() {
-      const area = _ol_geom_flat_area_.linearRings(
+      const area = linearRings(
         [0, 0, 0, 3, 3, 3, 3, 0, 1, 1, 2, 1, 2, 2, 1, 2], 0, [8, 16], 2);
       expect(area).to.be(8);
     });
diff --git a/test/spec/ol/geom/flat/center.test.js b/test/spec/ol/geom/flat/center.test.js
index 21a23bc959..bedb65b0a6 100644
--- a/test/spec/ol/geom/flat/center.test.js
+++ b/test/spec/ol/geom/flat/center.test.js
@@ -1,4 +1,4 @@
-import _ol_geom_flat_center_ from '../../../../../src/ol/geom/flat/center.js';
+import {linearRingss as linearRingssCenter} from '../../../../../src/ol/geom/flat/center.js';
 import MultiPolygon from '../../../../../src/ol/geom/MultiPolygon.js';
 
 
@@ -10,7 +10,7 @@ describe('ol.geom.flat.center', function() {
       const squareMultiPoly = new MultiPolygon([[
         [[0, 0], [0, 1], [1, 1], [1, 0], [0, 0]]
       ]]);
-      const got = _ol_geom_flat_center_.linearRingss(
+      const got = linearRingssCenter(
         squareMultiPoly.flatCoordinates,
         0,
         squareMultiPoly.endss_,
@@ -28,7 +28,7 @@ describe('ol.geom.flat.center', function() {
           [[3, 0], [3, 1], [4, 1], [4, 0], [3, 0]]
         ]
       ]);
-      const got = _ol_geom_flat_center_.linearRingss(
+      const got = linearRingssCenter(
         squareMultiPoly.flatCoordinates,
         0,
         squareMultiPoly.endss_,
@@ -42,7 +42,7 @@ describe('ol.geom.flat.center', function() {
         [[0, 0], [0, 5], [5, 5], [5, 0], [0, 0]],
         [[1, 1], [1, 4], [4, 4], [4, 1], [1, 1]]
       ]]);
-      const got = _ol_geom_flat_center_.linearRingss(
+      const got = linearRingssCenter(
         polywithHole.flatCoordinates,
         0,
         polywithHole.endss_,
diff --git a/test/spec/ol/geom/flat/contains.test.js b/test/spec/ol/geom/flat/contains.test.js
index 3853f230b5..ae7411834e 100644
--- a/test/spec/ol/geom/flat/contains.test.js
+++ b/test/spec/ol/geom/flat/contains.test.js
@@ -1,4 +1,4 @@
-import _ol_geom_flat_contains_ from '../../../../../src/ol/geom/flat/contains.js';
+import {linearRingContainsXY} from '../../../../../src/ol/geom/flat/contains.js';
 
 
 describe('ol.geom.flat.contains', function() {
@@ -11,27 +11,27 @@ describe('ol.geom.flat.contains', function() {
     describe('ol.geom.flat.contains.linearRingContainsXY', function() {
 
       it('returns true for point inside a simple polygon', function() {
-        expect(_ol_geom_flat_contains_.linearRingContainsXY(
+        expect(linearRingContainsXY(
           flatCoordinatesSimple, 0, flatCoordinatesSimple.length, 2, 0.5, 0.5)).to.be(true);
       });
 
       it('returns false for point outside a simple polygon', function() {
-        expect(_ol_geom_flat_contains_.linearRingContainsXY(
+        expect(linearRingContainsXY(
           flatCoordinatesSimple, 0, flatCoordinatesSimple.length, 2, 1.5, 1.5)).to.be(false);
       });
 
       it('returns true for point inside a non-simple polygon', function() {
-        expect(_ol_geom_flat_contains_.linearRingContainsXY(
+        expect(linearRingContainsXY(
           flatCoordinatesNonSimple, 0, flatCoordinatesNonSimple.length, 2, 1, 1)).to.be(true);
       });
 
       it('returns true for point inside an overlap of a non-simple polygon', function() {
-        expect(_ol_geom_flat_contains_.linearRingContainsXY(
+        expect(linearRingContainsXY(
           flatCoordinatesNonSimple, 0, flatCoordinatesNonSimple.length, 2, 1.5, 2.5)).to.be(true);
       });
 
       it('returns false for a point inside a hole of a non-simple polygon', function() {
-        expect(_ol_geom_flat_contains_.linearRingContainsXY(
+        expect(linearRingContainsXY(
           flatCoordinatesNonSimple, 0, flatCoordinatesNonSimple.length, 2, 2.5, 1.5)).to.be(false);
       });
 
diff --git a/test/spec/ol/geom/flat/flip.test.js b/test/spec/ol/geom/flat/flip.test.js
index 0d7e9c9d69..27511928ce 100644
--- a/test/spec/ol/geom/flat/flip.test.js
+++ b/test/spec/ol/geom/flat/flip.test.js
@@ -1,4 +1,4 @@
-import _ol_geom_flat_flip_ from '../../../../../src/ol/geom/flat/flip.js';
+import {flipXY} from '../../../../../src/ol/geom/flat/flip.js';
 
 
 describe('ol.geom.flat.flip', function() {
@@ -6,29 +6,25 @@ describe('ol.geom.flat.flip', function() {
   describe('ol.geom.flat.flip.flipXY', function() {
 
     it('can flip XY coordinates', function() {
-      const flatCoordinates = _ol_geom_flat_flip_.flipXY([1, 2, 3, 4], 0, 4, 2);
+      const flatCoordinates = flipXY([1, 2, 3, 4], 0, 4, 2);
       expect(flatCoordinates).to.eql([2, 1, 4, 3]);
     });
 
     it('can flip XY coordinates while preserving other dimensions', function() {
-      const flatCoordinates = _ol_geom_flat_flip_.flipXY(
-        [1, 2, 3, 4, 5, 6, 7, 8], 0, 8, 4);
+      const flatCoordinates = flipXY([1, 2, 3, 4, 5, 6, 7, 8], 0, 8, 4);
       expect(flatCoordinates).to.eql([2, 1, 3, 4, 6, 5, 7, 8]);
     });
 
     it('can flip XY coordinates in place', function() {
       const flatCoordinates = [1, 2, 3, 4];
-      expect(_ol_geom_flat_flip_.flipXY(
-        flatCoordinates, 0, 4, 2, flatCoordinates)).to.be(flatCoordinates);
+      expect(flipXY(flatCoordinates, 0, 4, 2, flatCoordinates)).to.be(flatCoordinates);
       expect(flatCoordinates).to.eql([2, 1, 4, 3]);
     });
 
     it('can flip XY coordinates in place while preserving other dimensions',
       function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9];
-        expect(_ol_geom_flat_flip_.flipXY(
-          flatCoordinates, 0, 9, 3, flatCoordinates)).
-          to.be(flatCoordinates);
+        expect(flipXY(flatCoordinates, 0, 9, 3, flatCoordinates)).to.be(flatCoordinates);
         expect(flatCoordinates).to.eql([2, 1, 3, 5, 4, 6, 8, 7, 9]);
       });
 
diff --git a/test/spec/ol/geom/flat/reverse.test.js b/test/spec/ol/geom/flat/reverse.test.js
index 9709358613..ba1d5d84e9 100644
--- a/test/spec/ol/geom/flat/reverse.test.js
+++ b/test/spec/ol/geom/flat/reverse.test.js
@@ -1,4 +1,4 @@
-import _ol_geom_flat_reverse_ from '../../../../../src/ol/geom/flat/reverse.js';
+import {coordinates as reverseCoordinates} from '../../../../../src/ol/geom/flat/reverse.js';
 
 
 describe('ol.geom.flat.reverse', function() {
@@ -9,36 +9,31 @@ describe('ol.geom.flat.reverse', function() {
 
       it('can reverse empty flat coordinates', function() {
         const flatCoordinates = [];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 2);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
         expect(flatCoordinates).to.be.empty();
       });
 
       it('can reverse one flat coordinates', function() {
         const flatCoordinates = [1, 2];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 2);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
         expect(flatCoordinates).to.eql([1, 2]);
       });
 
       it('can reverse two flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 2);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
         expect(flatCoordinates).to.eql([3, 4, 1, 2]);
       });
 
       it('can reverse three flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 2);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
         expect(flatCoordinates).to.eql([5, 6, 3, 4, 1, 2]);
       });
 
       it('can reverse four flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 2);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 2);
         expect(flatCoordinates).to.eql([7, 8, 5, 6, 3, 4, 1, 2]);
       });
 
@@ -48,36 +43,31 @@ describe('ol.geom.flat.reverse', function() {
 
       it('can reverse empty flat coordinates', function() {
         const flatCoordinates = [];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 3);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
         expect(flatCoordinates).to.be.empty();
       });
 
       it('can reverse one flat coordinates', function() {
         const flatCoordinates = [1, 2, 3];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 3);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
         expect(flatCoordinates).to.eql([1, 2, 3]);
       });
 
       it('can reverse two flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 3);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
         expect(flatCoordinates).to.eql([4, 5, 6, 1, 2, 3]);
       });
 
       it('can reverse three flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 3);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
         expect(flatCoordinates).to.eql([7, 8, 9, 4, 5, 6, 1, 2, 3]);
       });
 
       it('can reverse four flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 3);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 3);
         expect(flatCoordinates).to.eql([10, 11, 12, 7, 8, 9, 4, 5, 6, 1, 2, 3]);
       });
 
@@ -87,37 +77,32 @@ describe('ol.geom.flat.reverse', function() {
 
       it('can reverse empty flat coordinates', function() {
         const flatCoordinates = [];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 4);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
         expect(flatCoordinates).to.be.empty();
       });
 
       it('can reverse one flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 4);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
         expect(flatCoordinates).to.eql([1, 2, 3, 4]);
       });
 
       it('can reverse two flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 4);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
         expect(flatCoordinates).to.eql([5, 6, 7, 8, 1, 2, 3, 4]);
       });
 
       it('can reverse three flat coordinates', function() {
         const flatCoordinates = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 4);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
         expect(flatCoordinates).to.eql([9, 10, 11, 12, 5, 6, 7, 8, 1, 2, 3, 4]);
       });
 
       it('can reverse four flat coordinates', function() {
         const flatCoordinates =
             [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
-        _ol_geom_flat_reverse_.coordinates(
-          flatCoordinates, 0, flatCoordinates.length, 4);
+        reverseCoordinates(flatCoordinates, 0, flatCoordinates.length, 4);
         expect(flatCoordinates).to.eql(
           [13, 14, 15, 16, 9, 10, 11, 12, 5, 6, 7, 8, 1, 2, 3, 4]);
       });
diff --git a/test/spec/ol/geom/flat/segments.test.js b/test/spec/ol/geom/flat/segments.test.js
index e0e7315323..8f36a891ea 100644
--- a/test/spec/ol/geom/flat/segments.test.js
+++ b/test/spec/ol/geom/flat/segments.test.js
@@ -1,4 +1,4 @@
-import _ol_geom_flat_segments_ from '../../../../../src/ol/geom/flat/segments.js';
+import {forEach as forEachSegment} from '../../../../../src/ol/geom/flat/segments.js';
 
 
 describe('ol.geom.flat.segments', function() {
@@ -17,8 +17,7 @@ describe('ol.geom.flat.segments', function() {
         const spy = sinon.spy(function(point1, point2) {
           args.push([point1[0], point1[1], point2[0], point2[1]]);
         });
-        const ret = _ol_geom_flat_segments_.forEach(
-          flatCoordinates, offset, end, stride, spy);
+        const ret = forEachSegment(flatCoordinates, offset, end, stride, spy);
         expect(spy.callCount).to.be(3);
         expect(args[0][0]).to.be(0);
         expect(args[0][1]).to.be(0);
@@ -42,8 +41,7 @@ describe('ol.geom.flat.segments', function() {
           args.push([point1[0], point1[1], point2[0], point2[1]]);
           return true;
         });
-        const ret = _ol_geom_flat_segments_.forEach(
-          flatCoordinates, offset, end, stride, spy);
+        const ret = forEachSegment(flatCoordinates, offset, end, stride, spy);
         expect(spy.callCount).to.be(1);
         expect(args[0][0]).to.be(0);
         expect(args[0][1]).to.be(0);
diff --git a/test/spec/ol/geom/flat/topologyflatgeom.test.js b/test/spec/ol/geom/flat/topologyflatgeom.test.js
index d9a6dc5865..f0d17999d0 100644
--- a/test/spec/ol/geom/flat/topologyflatgeom.test.js
+++ b/test/spec/ol/geom/flat/topologyflatgeom.test.js
@@ -1,4 +1,4 @@
-import _ol_geom_flat_topology_ from '../../../../../src/ol/geom/flat/topology.js';
+import {lineStringIsClosed} from '../../../../../src/ol/geom/flat/topology.js';
 
 describe('ol.geom.flat.topology', function() {
 
@@ -6,23 +6,23 @@ describe('ol.geom.flat.topology', function() {
 
     it('identifies closed lines aka boundaries', function() {
       const flatCoordinates = [0, 0, 3, 0, 0, 3, 0, 0];
-      const isClosed = _ol_geom_flat_topology_.lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
+      const isClosed = lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
       expect(isClosed).to.be(true);
     });
 
     it('identifies regular linestrings', function() {
       const flatCoordinates = [0, 0, 3, 0, 0, 3, 5, 2];
-      const isClosed = _ol_geom_flat_topology_.lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
+      const isClosed = lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
       expect(isClosed).to.be(false);
     });
 
     it('identifies degenerate boundaries', function() {
       let flatCoordinates = [0, 0, 3, 0, 0, 0];
-      let isClosed = _ol_geom_flat_topology_.lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
+      let isClosed = lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
       expect(isClosed).to.be(false);
 
       flatCoordinates = [0, 0, 1, 1, 3, 3, 5, 5, 0, 0];
-      isClosed = _ol_geom_flat_topology_.lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
+      isClosed = lineStringIsClosed(flatCoordinates, 0, flatCoordinates.length, 2);
       expect(isClosed).to.be(false);
     });