diff --git a/src/ol/extent.js b/src/ol/extent.js
index 67d11ad039..c073fb3191 100644
--- a/src/ol/extent.js
+++ b/src/ol/extent.js
@@ -1,7 +1,6 @@
 /**
  * @module ol/extent
  */
-import Corner from './extent/Corner.js';
 import Relationship from './extent/Relationship.js';
 import {assert} from './asserts.js';
 
@@ -11,6 +10,11 @@ import {assert} from './asserts.js';
  * @api
  */
 
+/**
+ * Extent corner.
+ * @typedef {'bottom-left' | 'bottom-right' | 'top-left' | 'top-right'} Corner
+ */
+
 /**
  * Build an extent that includes all given coordinates.
  *
@@ -484,18 +488,18 @@ export function getCenter(extent) {
 /**
  * Get a corner coordinate of an extent.
  * @param {Extent} extent Extent.
- * @param {import("./extent/Corner.js").default} corner Corner.
+ * @param {Corner} corner Corner.
  * @return {import("./coordinate.js").Coordinate} Corner coordinate.
  */
 export function getCorner(extent, corner) {
   let coordinate;
-  if (corner === Corner.BOTTOM_LEFT) {
+  if (corner === 'bottom-left') {
     coordinate = getBottomLeft(extent);
-  } else if (corner === Corner.BOTTOM_RIGHT) {
+  } else if (corner === 'bottom-right') {
     coordinate = getBottomRight(extent);
-  } else if (corner === Corner.TOP_LEFT) {
+  } else if (corner === 'top-left') {
     coordinate = getTopLeft(extent);
-  } else if (corner === Corner.TOP_RIGHT) {
+  } else if (corner === 'top-right') {
     coordinate = getTopRight(extent);
   } else {
     assert(false, 13); // Invalid corner
diff --git a/src/ol/extent/Corner.js b/src/ol/extent/Corner.js
deleted file mode 100644
index 027293e7a5..0000000000
--- a/src/ol/extent/Corner.js
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * @module ol/extent/Corner
- */
-
-/**
- * Extent corner.
- * @enum {string}
- */
-export default {
-  BOTTOM_LEFT: 'bottom-left',
-  BOTTOM_RIGHT: 'bottom-right',
-  TOP_LEFT: 'top-left',
-  TOP_RIGHT: 'top-right',
-};
diff --git a/src/ol/tilegrid.js b/src/ol/tilegrid.js
index c342cf6e8c..cdaab9c9fd 100644
--- a/src/ol/tilegrid.js
+++ b/src/ol/tilegrid.js
@@ -1,7 +1,6 @@
 /**
  * @module ol/tilegrid
  */
-import Corner from './extent/Corner.js';
 import TileGrid from './tilegrid/TileGrid.js';
 import Units from './proj/Units.js';
 import {DEFAULT_MAX_ZOOM, DEFAULT_TILE_SIZE} from './tilegrid/common.js';
@@ -57,11 +56,11 @@ export function wrapX(tileGrid, tileCoord, projection) {
  *     DEFAULT_MAX_ZOOM).
  * @param {number|import("./size.js").Size} [opt_tileSize] Tile size (default uses
  *     DEFAULT_TILE_SIZE).
- * @param {import("./extent/Corner.js").default} [opt_corner] Extent corner (default is `'top-left'`).
+ * @param {import("./extent.js").Corner} [opt_corner] Extent corner (default is `'top-left'`).
  * @return {!TileGrid} TileGrid instance.
  */
 export function createForExtent(extent, opt_maxZoom, opt_tileSize, opt_corner) {
-  const corner = opt_corner !== undefined ? opt_corner : Corner.TOP_LEFT;
+  const corner = opt_corner !== undefined ? opt_corner : 'top-left';
 
   const resolutions = resolutionsFromExtent(extent, opt_maxZoom, opt_tileSize);
 
@@ -153,7 +152,7 @@ function resolutionsFromExtent(
  *     DEFAULT_MAX_ZOOM).
  * @param {number|import("./size.js").Size} [opt_tileSize] Tile size (default uses
  *     DEFAULT_TILE_SIZE).
- * @param {import("./extent/Corner.js").default} [opt_corner] Extent corner (default is `'top-left'`).
+ * @param {import("./extent.js").Corner} [opt_corner] Extent corner (default is `'top-left'`).
  * @return {!TileGrid} TileGrid instance.
  */
 export function createForProjection(