diff --git a/src/abstract_client.cpp b/src/abstract_client.cpp
index ff61825915..fbb0b038b8 100644
--- a/src/abstract_client.cpp
+++ b/src/abstract_client.cpp
@@ -2036,7 +2036,7 @@ bool AbstractClient::isActiveFullScreen() const
     // according to NETWM spec implementation notes suggests
     // "focused windows having state _NET_WM_STATE_FULLSCREEN" to be on the highest layer.
     // we'll also take the screen into account
-    return ac && (ac == this || ac->output() != output()|| ac->allMainClients().contains(const_cast<AbstractClient*>(this)));
+    return ac && (ac == this || !ac->isOnOutput(output()) || ac->allMainClients().contains(const_cast<AbstractClient*>(this)));
 }
 
 #define BORDER(which) \