diff --git a/placement.cpp b/placement.cpp
index add860e60b..635ff32542 100644
--- a/placement.cpp
+++ b/placement.cpp
@@ -451,7 +451,7 @@ void Placement::placeCascaded(Client* c, QRect& area, Policy nextPlacement)
 /*!
   Place windows centered, on top of all others
 */
-void Placement::placeCentered(Client* c, const QRect& area, Policy /*next*/)
+void Placement::placeCentered(AbstractClient* c, const QRect& area, Policy /*next*/)
 {
 
     // get the maximum allowed windows space and desk's origin
diff --git a/placement.h b/placement.h
index ca0b10f401..5c0bc0b6b1 100644
--- a/placement.h
+++ b/placement.h
@@ -68,7 +68,7 @@ public:
     void placeCascaded(Client* c, QRect& area, Policy next = Unknown);
     void placeSmart(Client* c, const QRect& area, Policy next = Unknown);
     void placeMaximizing(Client* c, QRect& area, Policy next = Unknown);
-    void placeCentered(Client* c, const QRect& area, Policy next = Unknown);
+    void placeCentered(AbstractClient* c, const QRect& area, Policy next = Unknown);
     void placeZeroCornered(AbstractClient* c, const QRect& area, Policy next = Unknown);
     void placeDialog(Client* c, QRect& area, Policy next = Unknown);
     void placeUtility(Client* c, QRect& area, Policy next = Unknown);