diff --git a/src/ol/format/KML.js b/src/ol/format/KML.js
index 46d4674911..8775ecf583 100644
--- a/src/ol/format/KML.js
+++ b/src/ol/format/KML.js
@@ -1117,7 +1117,8 @@ export function readFlatCoordinates(node) {
   const flatCoordinates = [];
   // The KML specification states that coordinate tuples should not include
   // spaces, but we tolerate them.
-  const re = /^\s*([+\-]?\d*\.?\d+(?:e[+\-]?\d+)?)\s*,\s*([+\-]?\d*\.?\d+(?:e[+\-]?\d+)?)(?:\s*,\s*([+\-]?\d*\.?\d+(?:e[+\-]?\d+)?))?\s*/i;
+  s = s.replace(/\s*,\s*/g, ',');
+  const re = /^\s*([+\-]?\d*\.?\d+(?:e[+\-]?\d+)?),([+\-]?\d*\.?\d+(?:e[+\-]?\d+)?)(?:\s+|,|$)(?:([+\-]?\d*\.?\d+(?:e[+\-]?\d+)?)(?:\s+|$))?\s*/i;
   let m;
   while ((m = re.exec(s))) {
     const x = parseFloat(m[1]);
diff --git a/test/spec/ol/format/kml.test.js b/test/spec/ol/format/kml.test.js
index 8df3ea6e99..0fe434e3f6 100644
--- a/test/spec/ol/format/kml.test.js
+++ b/test/spec/ol/format/kml.test.js
@@ -468,6 +468,54 @@ describe('ol.format.KML', function () {
           expect(g.get('altitudeMode')).to.be('absolute');
         });
 
+        it('can read XY coordinates', function () {
+          const text =
+            '<kml xmlns="http://earth.google.com/kml/2.2">' +
+            '  <Placemark>' +
+            '    <LineString>' +
+            '      <coordinates>1,2 3,4</coordinates>' +
+            '      <extrude>0</extrude>' +
+            '      <tessellate>1</tessellate>' +
+            '      <altitudeMode>absolute</altitudeMode>' +
+            '    </LineString>' +
+            '  </Placemark>' +
+            '</kml>';
+          const fs = format.readFeatures(text);
+          expect(fs).to.have.length(1);
+          const f = fs[0];
+          expect(f).to.be.an(Feature);
+          const g = f.getGeometry();
+          expect(g).to.be.an(LineString);
+          expect(g.getCoordinates()).to.eql([
+            [1, 2, 0],
+            [3, 4, 0],
+          ]);
+        });
+
+        it('can read empty Z coordinates', function () {
+          const text =
+            '<kml xmlns="http://earth.google.com/kml/2.2">' +
+            '  <Placemark>' +
+            '    <LineString>' +
+            '      <coordinates>1,2, 3,4,</coordinates>' +
+            '      <extrude>0</extrude>' +
+            '      <tessellate>1</tessellate>' +
+            '      <altitudeMode>absolute</altitudeMode>' +
+            '    </LineString>' +
+            '  </Placemark>' +
+            '</kml>';
+          const fs = format.readFeatures(text);
+          expect(fs).to.have.length(1);
+          const f = fs[0];
+          expect(f).to.be.an(Feature);
+          const g = f.getGeometry();
+          expect(g).to.be.an(LineString);
+          expect(g.getCoordinates()).to.eql([
+            [1, 2, 0],
+            [3, 4, 0],
+          ]);
+        });
+
         it('can write XY LineString geometries', function () {
           const layout = 'XY';
           const lineString = new LineString(