diff --git a/wasp/wasp.py b/wasp/wasp.py
index c9f40db..a78f5da 100644
--- a/wasp/wasp.py
+++ b/wasp/wasp.py
@@ -176,7 +176,7 @@ class Manager():
 
     def unregister(self, cls):
         for app in self.launcher_ring:
-            if instanceof(app, cls):
+            if isinstance(app, cls):
                 self.launcher_ring.remove(app)
                 break