Index: tests/runtests.py
===================================================================
--- tests/runtests.py	(revision 7261)
+++ tests/runtests.py	(working copy)
@@ -118,7 +118,6 @@
     get_apps()
 
     # Load all the test model apps.
-    test_models = []
     for model_dir, model_name in get_test_models():
         model_label = '.'.join([model_dir, model_name])
         try:
@@ -142,6 +141,13 @@
         model_label = '.'.join([model_dir, model_name])
         if not test_labels or model_name in test_labels:
             extra_tests.append(InvalidModelTestCase(model_label))
+    
+    # "invalid_models" is not an app, so we cannot pass it in with the other 
+    # test_labels
+    try:
+        test_labels.remove("invalid_models")
+    except ValueError:
+        pass
 
     # Run the test suite, including the extra validation tests.
     from django.test.simple import run_tests