diff --git a/AUTHORS b/AUTHORS
index e9316b700d..44cee256a7 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -66,6 +66,7 @@ answer newbie questions, and generally made Django that much better:
     lakin.wecker@gmail.com
     Stuart Langridge <http://www.kryogenix.org/>
     Eugene Lazutkin <http://lazutkin.com/blog/>
+    Christopher Lenz <http://www.cmlenz.net/>
     limodou
     Martin Maney <http://www.chipy.org/Martin_Maney>
     Maniac <http://www.softwaremaniacs.org/>
diff --git a/django/core/management.py b/django/core/management.py
index 7b498b2546..88c4c3c251 100644
--- a/django/core/management.py
+++ b/django/core/management.py
@@ -224,7 +224,7 @@ def get_sql_delete(app):
              connection.rollback()
          else:
              output.append("DROP TABLE %s;" % backend.quote_name(klass._meta.db_table))
-             if references_to_delete.has_key(klass):
+             if backend.supports_constraints and references_to_delete.has_key(klass):
                  for rel_class, f in references_to_delete[klass]:
                      table = rel_class._meta.db_table
                      col = f.column