diff --git a/client.h b/client.h
index 74f8cd4e73..ce20e47652 100644
--- a/client.h
+++ b/client.h
@@ -807,7 +807,7 @@ private:
     static void sendClientMessage(xcb_window_t w, xcb_atom_t a, xcb_atom_t protocol,
                                   long data1 = 0, long data2 = 0, long data3 = 0);
 
-    void embedClient(Window w, const XWindowAttributes& attr);
+    void embedClient(xcb_window_t w, const XWindowAttributes& attr);
     void detectNoBorder();
     void destroyDecoration();
     void updateFrameExtents();
diff --git a/manage.cpp b/manage.cpp
index e736cf82d8..47d584607f 100644
--- a/manage.cpp
+++ b/manage.cpp
@@ -626,10 +626,10 @@ bool Client::manage(xcb_window_t w, bool isMapped)
 }
 
 // Called only from manage()
-void Client::embedClient(Window w, const XWindowAttributes& attr)
+void Client::embedClient(xcb_window_t w, const XWindowAttributes& attr)
 {
     assert(m_client == XCB_WINDOW_NONE);
-    assert(frameId() == None);
+    assert(frameId() == XCB_WINDOW_NONE);
     assert(m_wrapper == XCB_WINDOW_NONE);
     m_client = w;