diff --git a/lib/que.rb b/lib/que.rb
index 89459472..99c2686c 100644
--- a/lib/que.rb
+++ b/lib/que.rb
@@ -80,7 +80,7 @@ def default_queue
     end
 
     def server?
-      defined?(Que::CommandLineInterface).nil?
+      !defined?(Que::CommandLineInterface).nil?
     end
 
     # Support simple integration with many common connection pools.