diff --git a/ofdpa/flows.py b/ofdpa/flows.py
index 851036d..c03c933 100755
--- a/ofdpa/flows.py
+++ b/ofdpa/flows.py
@@ -1638,6 +1638,6 @@
                     verify_no_other_packets( self )
         finally:
             delete_all_flows( self.controller )
-            delete_groups( self.controller, Groups )
+            delete_groups( self.controller, groups )
             delete_all_groups( self.controller )