diff --git a/tests/gis_tests/geoapp/test_functions.py b/tests/gis_tests/geoapp/test_functions.py
index b518f9cb53..0c76aa9730 100644
--- a/tests/gis_tests/geoapp/test_functions.py
+++ b/tests/gis_tests/geoapp/test_functions.py
@@ -386,7 +386,8 @@ class GISFunctionsTests(FuncTestMixin, TestCase):
     @skipUnlessDBFeature("has_MemSize_function")
     def test_memsize(self):
         ptown = City.objects.annotate(size=functions.MemSize('point')).get(name='Pueblo')
-        self.assertTrue(20 <= ptown.size <= 40)  # Exact value may depend on PostGIS version
+        # Exact value depends on database and version.
+        self.assertTrue(20 <= ptown.size <= 105)
 
     @skipUnlessDBFeature("has_NumGeom_function")
     def test_num_geom(self):