diff --git a/src/ol/proj/epsg3857.js b/src/ol/proj/epsg3857.js
index 1d7afb2083..16a69df67d 100644
--- a/src/ol/proj/epsg3857.js
+++ b/src/ol/proj/epsg3857.js
@@ -71,6 +71,7 @@ export const PROJECTIONS = [
   new EPSG3857Projection('EPSG:102100'),
   new EPSG3857Projection('EPSG:102113'),
   new EPSG3857Projection('EPSG:900913'),
+  new EPSG3857Projection('http://www.opengis.net/def/crs/EPSG/0/3857'),
   new EPSG3857Projection('http://www.opengis.net/gml/srs/epsg.xml#3857'),
 ];
 
diff --git a/src/ol/proj/epsg4326.js b/src/ol/proj/epsg4326.js
index 5a720abf2e..9b616d4e04 100644
--- a/src/ol/proj/epsg4326.js
+++ b/src/ol/proj/epsg4326.js
@@ -63,5 +63,7 @@ export const PROJECTIONS = [
   new EPSG4326Projection('EPSG:4326', 'neu'),
   new EPSG4326Projection('urn:ogc:def:crs:OGC:1.3:CRS84'),
   new EPSG4326Projection('urn:ogc:def:crs:OGC:2:84'),
+  new EPSG4326Projection('http://www.opengis.net/def/crs/OGC/1.3/CRS84', 'neu'),
   new EPSG4326Projection('http://www.opengis.net/gml/srs/epsg.xml#4326', 'neu'),
+  new EPSG4326Projection('http://www.opengis.net/def/crs/EPSG/0/4326', 'neu'),
 ];
diff --git a/test/node/ol/proj.test.js b/test/node/ol/proj.test.js
index 057c860764..b2a723b233 100644
--- a/test/node/ol/proj.test.js
+++ b/test/node/ol/proj.test.js
@@ -190,12 +190,14 @@ describe('ol/proj.js', function () {
       });
     }
 
-    it('gives that 3857, 102100, 102113, 900913 are equivalent ', function () {
+    it('treats EPSG:3857 variants as equivalent', function () {
       _testAllEquivalent([
         'EPSG:3857',
         'EPSG:102100',
         'EPSG:102113',
         'EPSG:900913',
+        'http://www.opengis.net/def/crs/EPSG/0/3857',
+        'http://www.opengis.net/gml/srs/epsg.xml#3857',
       ]);
     });
 
@@ -217,18 +219,17 @@ describe('ol/proj.js', function () {
       _testAllEquivalent(['EPSG:3857', 'EPSG:3857']);
     });
 
-    it(
-      'gives that CRS:84, urn:ogc:def:crs:EPSG:6.6:4326, EPSG:4326, ' +
-        'urn:x-ogc:def:crs:EPSG:6.6:4326 are equivalent',
-      function () {
-        _testAllEquivalent([
-          'CRS:84',
-          'urn:ogc:def:crs:EPSG:6.6:4326',
-          'urn:x-ogc:def:crs:EPSG:6.6:4326',
-          'EPSG:4326',
-        ]);
-      }
-    );
+    it('treats EPSG:4326 variants as equivalent', function () {
+      _testAllEquivalent([
+        'CRS:84',
+        'urn:ogc:def:crs:EPSG:6.6:4326',
+        'urn:x-ogc:def:crs:EPSG:6.6:4326',
+        'EPSG:4326',
+        'http://www.opengis.net/def/crs/OGC/1.3/CRS84',
+        'http://www.opengis.net/gml/srs/epsg.xml#4326',
+        'http://www.opengis.net/def/crs/EPSG/0/4326',
+      ]);
+    });
 
     it('requires code and units to be equal for projection evquivalence', function () {
       const proj1 = new Projection({