diff --git a/utils.cpp b/utils.cpp
index 29b73f0f91..f725a0e1d4 100644
--- a/utils.cpp
+++ b/utils.cpp
@@ -72,7 +72,7 @@ StrutRect::StrutRect(const StrutRect& other)
 // Motif
 //************************************
 
-void Motif::readFlags(WId w, bool& got_noborder, bool& noborder,
+void Motif::readFlags(xcb_window_t w, bool& got_noborder, bool& noborder,
                       bool& resize, bool& move, bool& minimize, bool& maximize, bool& close)
 {
     Atom type;
diff --git a/utils.h b/utils.h
index 620c2d0f23..8512565024 100644
--- a/utils.h
+++ b/utils.h
@@ -166,7 +166,7 @@ public:
     // property.  If it explicitly requests that decorations be shown
     // or hidden, 'got_noborder' is set to true and 'noborder' is set
     // appropriately.
-    static void readFlags(Window w, bool& got_noborder, bool& noborder,
+    static void readFlags(xcb_window_t w, bool& got_noborder, bool& noborder,
                           bool& resize, bool& move, bool& minimize, bool& maximize,
                           bool& close);
     struct MwmHints {