diff --git a/dlls/user/tests/win.c b/dlls/user/tests/win.c
index d070d546285..1dd73c11893 100644
--- a/dlls/user/tests/win.c
+++ b/dlls/user/tests/win.c
@@ -928,7 +928,7 @@ static void test_shell_window(void)
 
 static const char mdi_lParam_test_message[] = "just a test string";
 
-static void test_MDI_create(HWND parent, HWND mdi_client)
+static void test_MDI_create(HWND parent, HWND mdi_client, INT first_id)
 {
     MDICREATESTRUCTA mdi_cs;
     HWND mdi_child;
@@ -947,12 +947,14 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     mdi_cs.lParam = (LPARAM)mdi_lParam_test_message;
     mdi_child = (HWND)SendMessageA(mdi_client, WM_MDICREATE, 0, (LPARAM)&mdi_cs);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
     ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
 
     mdi_cs.style = 0x7fffffff; /* without WS_POPUP */
     mdi_child = (HWND)SendMessageA(mdi_client, WM_MDICREATE, 0, (LPARAM)&mdi_cs);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
     ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
 
@@ -965,6 +967,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     else
     {
         ok(mdi_child != 0, "MDI child creation failed\n");
+        ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
         SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
         ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
     }
@@ -985,6 +988,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     }
     else
     {
+        ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
         SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
         ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
     }
@@ -996,6 +1000,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                  mdi_client, GetModuleHandle(0),
                                  (LPARAM)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
     ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
 
@@ -1006,6 +1011,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                  mdi_client, GetModuleHandle(0),
                                  (LPARAM)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
     ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
 
@@ -1022,6 +1028,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     else
     {
         ok(mdi_child != 0, "MDI child creation failed\n");
+        ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
         SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
         ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
     }
@@ -1043,6 +1050,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     }
     else
     {
+        ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
         SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
         ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
     }
@@ -1054,6 +1062,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
     ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
 
@@ -1064,6 +1073,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
     ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
 
@@ -1080,6 +1090,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     else
     {
         ok(mdi_child != 0, "MDI child creation failed\n");
+        ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
         SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
         ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
     }
@@ -1101,6 +1112,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
     }
     else
     {
+        ok(GetWindowLongA(mdi_child, GWL_ID) == first_id, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
         SendMessageA(mdi_client, WM_MDIDESTROY, (WPARAM)mdi_child, 0);
         ok(!IsWindow(mdi_child), "WM_MDIDESTROY failed\n");
     }
@@ -1124,6 +1136,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == 0, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     DestroyWindow(mdi_child);
 
     mdi_child = CreateWindowExA(0, "MDI_child_Class_2", "MDI child",
@@ -1133,6 +1146,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == 0, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     DestroyWindow(mdi_child);
 
     /* maximized child */
@@ -1143,6 +1157,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == 0, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     DestroyWindow(mdi_child);
 
     trace("Creating maximized child with a caption\n");
@@ -1153,6 +1168,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == 0, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     DestroyWindow(mdi_child);
 
     trace("Creating maximized child with a caption and a thick frame\n");
@@ -1163,6 +1179,7 @@ static void test_MDI_create(HWND parent, HWND mdi_client)
                                 mdi_client, 0, GetModuleHandle(0),
                                 (LPVOID)mdi_lParam_test_message);
     ok(mdi_child != 0, "MDI child creation failed\n");
+    ok(GetWindowLongA(mdi_child, GWL_ID) == 0, "wrong child id %ld\n", GetWindowLongA(mdi_child, GWL_ID));
     DestroyWindow(mdi_child);
 }
 
@@ -1466,7 +1483,7 @@ static LRESULT WINAPI mdi_main_wnd_procA(HWND hwnd, UINT msg, WPARAM wparam, LPA
                                          hwnd, 0, GetModuleHandle(0),
                                          (LPVOID)&client_cs);
             assert(mdi_client);
-            test_MDI_create(hwnd, mdi_client);
+            test_MDI_create(hwnd, mdi_client, client_cs.idFirstChild);
             DestroyWindow(mdi_client);
 
             /* MDIClient with MDIS_ALLCHILDSTYLES */
@@ -1478,7 +1495,7 @@ static LRESULT WINAPI mdi_main_wnd_procA(HWND hwnd, UINT msg, WPARAM wparam, LPA
                                          hwnd, 0, GetModuleHandle(0),
                                          (LPVOID)&client_cs);
             assert(mdi_client);
-            test_MDI_create(hwnd, mdi_client);
+            test_MDI_create(hwnd, mdi_client, client_cs.idFirstChild);
             DestroyWindow(mdi_client);
             break;
         }
diff --git a/include/win.h b/include/win.h
index 11deac68929..ce1025aac23 100644
--- a/include/win.h
+++ b/include/win.h
@@ -93,7 +93,7 @@ extern void WIN_DestroyThreadWindows( HWND hwnd );
 extern BOOL WIN_CreateDesktopWindow(void);
 extern BOOL WIN_IsWindowDrawable( HWND hwnd, BOOL );
 extern HWND *WIN_ListChildren( HWND hwnd );
-extern void MDI_CalcDefaultChildPos( HWND hwndClient, INT total, LPPOINT lpPos, INT delta );
+extern void MDI_CalcDefaultChildPos( HWND hwndClient, INT total, LPPOINT lpPos, INT delta, UINT *id );
 
 /* internal SendInput codes (FIXME) */
 #define WINE_INTERNAL_INPUT_MOUSE    (16+INPUT_MOUSE)
diff --git a/windows/mdi.c b/windows/mdi.c
index caeb695c485..c4b9e4c259d 100644
--- a/windows/mdi.c
+++ b/windows/mdi.c
@@ -247,17 +247,17 @@ static HWND MDI_GetWindow(MDICLIENTINFO *clientInfo, HWND hWnd, BOOL bNext,
  *
  *  It seems that the default height is about 2/3 of the client rect
  */
-void MDI_CalcDefaultChildPos( HWND hwndClient, INT total, LPPOINT lpPos, INT delta )
+void MDI_CalcDefaultChildPos( HWND hwndClient, INT total, LPPOINT lpPos, INT delta, UINT *id )
 {
     INT  nstagger;
     RECT rect;
-    INT  spacing = GetSystemMetrics(SM_CYCAPTION) +
-		     GetSystemMetrics(SM_CYFRAME) - 1;
+    INT spacing = GetSystemMetrics(SM_CYCAPTION) + GetSystemMetrics(SM_CYFRAME) - 1;
 
-    if (total < 0)
+    if (total < 0) /* we are called from CreateWindow */
     {
         MDICLIENTINFO *ci = get_client_info(hwndClient);
         total = ci ? ci->nTotalCreated : 0;
+        *id = ci->idFirstChild + ci->nActiveChildren;
     }
 
     GetClientRect( hwndClient, &rect );
@@ -688,7 +688,7 @@ static LONG MDICascade( HWND client, MDICLIENTINFO *ci )
             TRACE("move %p to (%ld,%ld) size [%ld,%ld]\n",
                   win_array[i], pos[0].x, pos[0].y, pos[1].x, pos[1].y);
 
-            MDI_CalcDefaultChildPos(client, n++, pos, delta);
+            MDI_CalcDefaultChildPos(client, n++, pos, delta, NULL);
             SetWindowPos( win_array[i], 0, pos[0].x, pos[0].y, pos[1].x, pos[1].y,
                           SWP_DRAWFRAME | SWP_NOACTIVATE | SWP_NOZORDER);
         }
diff --git a/windows/win.c b/windows/win.c
index 5f6190ed71c..b1de4a4ed1a 100644
--- a/windows/win.c
+++ b/windows/win.c
@@ -786,9 +786,11 @@ static void WIN_FixCoordinates( CREATESTRUCTA *cs, INT *sw)
         {
             if (cs->dwExStyle & WS_EX_MDICHILD)
             {
+                UINT id = 0;
                 POINT pos[2];
 
-                MDI_CalcDefaultChildPos(cs->hwndParent, -1, pos, 0);
+                MDI_CalcDefaultChildPos(cs->hwndParent, -1, pos, 0, &id);
+                if (!(cs->style & WS_POPUP)) cs->hMenu = (HMENU)id;
 
                 if (cs->x == CW_USEDEFAULT || cs->x == CW_USEDEFAULT16)
                 {