diff --git a/tests/regressiontests/multiple_database/tests.py b/tests/regressiontests/multiple_database/tests.py
index 782fe2bfc6..e6d224e302 100644
--- a/tests/regressiontests/multiple_database/tests.py
+++ b/tests/regressiontests/multiple_database/tests.py
@@ -652,7 +652,8 @@ class QueryTestCase(TestCase):
 
         new_bob_profile = UserProfile(flavor="spring surprise")
 
-        charlie = User(username='charlie',email='charlie@example.com')
+        # assigning a profile requires a explicit pk as the object isn't saved
+        charlie = User(pk=51, username='charlie', email='charlie@example.com')
         charlie.set_unusable_password()
 
         # initially, no db assigned