diff --git a/tests/src/python/test_provider_postgres.py b/tests/src/python/test_provider_postgres.py
index 832c3a466f8..7f482ae1603 100644
--- a/tests/src/python/test_provider_postgres.py
+++ b/tests/src/python/test_provider_postgres.py
@@ -158,8 +158,7 @@ class TestPyQgsPostgresProvider(unittest.TestCase, ProviderTestCase):
 
     # See http://hub.qgis.org/issues/14262
     def testSignedIdentifiers(self):
-        def test_query_attribute(dbconn, query, att, val, fidval):
-            ql = QgsVectorLayer('%s table="%s" (g) key=\'%s\' sql=' % (dbconn, query.replace('"', '\\"'), att), "testgeom", "postgres")
+        def test_layer(ql, att, val, fidval):
             self.assertTrue(ql.isValid())
             features = ql.getFeatures()
             att_idx = ql.fieldNameIndex(att)
@@ -169,9 +168,18 @@ class TestPyQgsPostgresProvider(unittest.TestCase, ProviderTestCase):
                 self.assertEqual(f.attributes()[att_idx], val)
                 self.assertEqual(f.id(), fidval)
             self.assertEqual(count, 1)
-        test_query_attribute(self.dbconn, '(SELECT -1::int4 i, NULL::geometry(Point) g)', 'i', -1, 4294967295)
-        test_query_attribute(self.dbconn, '(SELECT -2::int2 i, NULL::geometry(Point) g)', 'i', -2, 4294967294)
-        test_query_attribute(self.dbconn, '(SELECT -3::int8 i, NULL::geometry(Point) g)', 'i', -3, 1)
+
+        def test(dbconn, query, att, val, fidval):
+            table = query.replace('"', '\\"')
+            uri = '%s table="%s" (g) key=\'%s\'' % (dbconn, table, att)
+            ql = QgsVectorLayer(uri, "t", "postgres")
+            test_layer(ql, att, val, fidval)
+            # now with estimated metadata
+            uri += ' estimatedmetadata="true"'
+            test_layer(ql, att, val, fidval)
+        test(self.dbconn, '(SELECT -1::int4 i, NULL::geometry(Point) g)', 'i', -1, 4294967295)
+        test(self.dbconn, '(SELECT -2::int2 i, NULL::geometry(Point) g)', 'i', -2, 4294967294)
+        test(self.dbconn, '(SELECT -3::int8 i, NULL::geometry(Point) g)', 'i', -3, 1)
 
     def testPktIntInsert(self):
         vl = QgsVectorLayer('{} table="qgis_test"."{}" key="pk" sql='.format(self.dbconn, 'bikes_view'), "bikes_view", "postgres")