diff --git a/dlls/user32/winpos.c b/dlls/user32/winpos.c
index c2b35ec..d49be31 100644
--- a/dlls/user32/winpos.c
+++ b/dlls/user32/winpos.c
@@ -1227,6 +1227,8 @@ BOOL WINAPI ShowWindowAsync( HWND hwnd, INT cmd )
 BOOL WINAPI ShowWindow( HWND hwnd, INT cmd )
 {
     HWND full_handle;
+    LONG style;
+    BOOL wasVisible;
 
     if (is_broadcast(hwnd))
     {
@@ -1236,8 +1238,37 @@ BOOL WINAPI ShowWindow( HWND hwnd, INT cmd )
     if ((full_handle = WIN_IsCurrentThread( hwnd )))
         return show_window( full_handle, cmd );
 
-    if ((cmd == SW_HIDE) && !(GetWindowLongW( hwnd, GWL_STYLE ) & WS_VISIBLE))
-        return FALSE;
+    style = GetWindowLongW( hwnd, GWL_STYLE );
+    wasVisible = (style & WS_VISIBLE) != 0;
+
+    switch(cmd)
+    {
+        case SW_HIDE:
+            if (!wasVisible) return FALSE;
+            break;
+        case SW_SHOWMINNOACTIVE:
+        case SW_MINIMIZE:
+        case SW_FORCEMINIMIZE:
+        case SW_SHOWMINIMIZED:
+            if ((style & WS_MINIMIZE) && wasVisible) return TRUE;
+            break;
+        case SW_SHOWMAXIMIZED:
+            if ((style & WS_MAXIMIZE) && wasVisible) return TRUE;
+            break;
+        case SW_SHOWNA:
+            break;
+        case SW_SHOW:
+            if (wasVisible) return TRUE;
+            break;
+        case SW_SHOWNOACTIVATE:
+        case SW_RESTORE:
+        case SW_SHOWNORMAL:
+        case SW_SHOWDEFAULT:
+            if (!(style & (WS_MINIMIZE | WS_MAXIMIZE)) && wasVisible) return TRUE;
+            break;
+        default:
+            return wasVisible;
+    }
 
     return SendMessageW( hwnd, WM_WINE_SHOWWINDOW, cmd, 0 );
 }