diff --git a/src/core/providers/memory/qgsmemoryproviderutils.cpp b/src/core/providers/memory/qgsmemoryproviderutils.cpp
index cccc63c4cec..663395dd2b2 100644
--- a/src/core/providers/memory/qgsmemoryproviderutils.cpp
+++ b/src/core/providers/memory/qgsmemoryproviderutils.cpp
@@ -65,6 +65,8 @@ QgsVectorLayer *QgsMemoryProviderUtils::createMemoryLayer( const QString &name,
   {
     parts << QStringLiteral( "field=%1:%2" ).arg( field.name(), memoryLayerFieldType( field.type() ) );
   }
+  // required so that source differs between memory layers
+  parts << QStringLiteral( "uid=%1" ).arg( QUuid::createUuid().toString() );
 
   QString uri = geomType + '?' + parts.join( '&' );
 
diff --git a/tests/src/python/test_provider_memory.py b/tests/src/python/test_provider_memory.py
index 9edb563dfb9..fdcdf317a64 100644
--- a/tests/src/python/test_provider_memory.py
+++ b/tests/src/python/test_provider_memory.py
@@ -349,6 +349,10 @@ class TestPyQgsMemoryProvider(unittest.TestCase, ProviderTestCase):
         self.assertEqual(layer.name(), 'my name')
         self.assertTrue(layer.fields().isEmpty())
 
+        # similar layers should have unique sources
+        layer2 = QgsMemoryProviderUtils.createMemoryLayer('my name', QgsFields())
+        self.assertNotEqual(layer.source(), layer2.source())
+
         # geometry type
         layer = QgsMemoryProviderUtils.createMemoryLayer('my name', QgsFields(), QgsWkbTypes.Point)
         self.assertTrue(layer.isValid())