diff --git a/devops-service/providers/ec2.rb b/devops-service/providers/ec2.rb
index dbb5d6b..609186b 100644
--- a/devops-service/providers/ec2.rb
+++ b/devops-service/providers/ec2.rb
@@ -56,7 +56,7 @@ module Provider
     end
 
     def groups filters={}
-      g = self.compute.describe_security_groups(filters)
+      g = self.compute.describe_security_groups(filters || {})
       convert_groups(g.body["securityGroupInfo"])
     end