diff --git a/tests/aws/requests/elasticache/helper.rb b/tests/aws/requests/elasticache/helper.rb
index ae8b10b80..65c42178d 100644
--- a/tests/aws/requests/elasticache/helper.rb
+++ b/tests/aws/requests/elasticache/helper.rb
@@ -14,7 +14,7 @@ class AWS
         'OwnerId'                 => String,
       }
       SINGLE_SECURITY_GROUP = BASIC.merge('CacheSecurityGroup' => SECURITY_GROUP)
-      DESCRIBE_SECURITY_GROUPS = BASIC.merge('CacheSecurityGroups' => [SECURITY_GROUP])
+      DESCRIBE_SECURITY_GROUPS = {'CacheSecurityGroups' => [SECURITY_GROUP]}
 
       # Cache Parameter Groups
       PARAMETER_GROUP = {