foo.diff

diff --git a/django/contrib/gis/tests/tests.py b/django/contrib/gis/tests/tests.py
index cc52d24..540d495 100644
--- a/django/contrib/gis/tests/tests.py
+++ b/django/contrib/gis/tests/tests.py
@@ -16,7 +16,7 @@ except ImproperlyConfigured as e:
     # an ImportError into an ImproperlyConfigured.
     # Here, we make sure we're only catching this specific case and not another
     # ImproperlyConfigured one.
-    if e.args and e.args[0].startswith('Could not import user-defined GEOMETRY_BACKEND'):
+    if e.args and e.args[0] and e.args[0].startswith('Could not import user-defined GEOMETRY_BACKEND'):
         HAS_POSTGRES = False
     else:
         six.reraise(*sys.exc_info())