diff --git a/src/core/qgsvectorlayerutils.cpp b/src/core/qgsvectorlayerutils.cpp
index 29653a98bac..0ae2ab27e1c 100644
--- a/src/core/qgsvectorlayerutils.cpp
+++ b/src/core/qgsvectorlayerutils.cpp
@@ -14,16 +14,31 @@
  ***************************************************************************/
 
 #include "qgsvectorlayerutils.h"
+#include "qgsvectordataprovider.h"
 
 bool QgsVectorLayerUtils::valueExists( const QgsVectorLayer* layer, int fieldIndex, const QVariant& value, const QgsFeatureIds& ignoreIds )
 {
   if ( !layer )
     return false;
 
-  if ( fieldIndex < 0 || fieldIndex >= layer->fields().count() )
+  QgsFields fields = layer->fields();
+
+  if ( fieldIndex < 0 || fieldIndex >= fields.count() )
     return false;
 
-  QString fieldName = layer->fields().at( fieldIndex ).name();
+  // check - if value is a provider side defaultValueClause then we exclude it from the check
+  if ( fields.fieldOrigin( fieldIndex ) == QgsFields::OriginProvider )
+  {
+    int providerIdx = fields.fieldOriginIndex( fieldIndex );
+    QString providerDefaultClause = layer->dataProvider()->defaultValueClause( providerIdx );
+    if ( !providerDefaultClause.isEmpty() && value.toString() == providerDefaultClause )
+    {
+      // exempt from check
+      return false;
+    }
+  }
+
+  QString fieldName = fields.at( fieldIndex ).name();
 
   // build up an optimised feature request
   QgsFeatureRequest request;
diff --git a/tests/src/python/test_provider_postgres.py b/tests/src/python/test_provider_postgres.py
index 97ddb8ab3f5..d483da905e1 100644
--- a/tests/src/python/test_provider_postgres.py
+++ b/tests/src/python/test_provider_postgres.py
@@ -29,7 +29,8 @@ from qgis.core import (
     QgsField,
     QgsFieldConstraints,
     QgsDataProvider,
-    NULL
+    NULL,
+    QgsVectorLayerUtils
 )
 from qgis.gui import QgsEditorWidgetRegistry
 from qgis.PyQt.QtCore import QSettings, QDate, QTime, QDateTime, QVariant
@@ -516,6 +517,18 @@ class TestPyQgsPostgresProvider(unittest.TestCase, ProviderTestCase):
         self.assertTrue(vl.fields().at(0).constraints().constraints() & QgsFieldConstraints.ConstraintUnique)
         self.assertTrue(vl.fieldConstraints(0) & QgsFieldConstraints.ConstraintUnique)
 
+    def testVectorLayerUtilsUniqueWithProviderDefault(self):
+        vl = QgsVectorLayer('%s table="qgis_test"."someData" sql=' % (self.dbconn), "someData", "postgres")
+        default_clause = 'nextval(\'qgis_test."someData_pk_seq"\'::regclass)'
+        self.assertEqual(vl.dataProvider().defaultValueClause(0), default_clause)
+        self.assertTrue(QgsVectorLayerUtils.valueExists(vl, 0, 4))
+
+        vl.startEditing()
+        f = QgsFeature(vl.fields())
+        f.setAttribute(0, default_clause)
+        self.assertTrue(vl.addFeatures([f]))
+        self.assertFalse(QgsVectorLayerUtils.valueExists(vl, 0, default_clause))
+
     # See http://hub.qgis.org/issues/15188
     def testNumericPrecision(self):
         uri = 'point?field=f1:int'