diff --git a/placement.cpp b/placement.cpp
index 722e782d38..5293be0704 100644
--- a/placement.cpp
+++ b/placement.cpp
@@ -168,7 +168,7 @@ void Placement::placeAtRandom(Client* c, const QRect& area, Policy /*next*/)
 }
 
 // TODO: one day, there'll be C++11 ...
-static inline bool isIrrelevant(const Client *client, const Client *regarding, int desktop)
+static inline bool isIrrelevant(const AbstractClient *client, const AbstractClient *regarding, int desktop)
 {
     if (!client)
         return true;