diff --git a/patches/patchinstall.sh b/patches/patchinstall.sh
index 80638a38..537830bf 100755
--- a/patches/patchinstall.sh
+++ b/patches/patchinstall.sh
@@ -356,6 +356,7 @@ patch_enable_all ()
 	enable_winex11_key_translation="$1"
 	enable_winex11_mouse_movements="$1"
 	enable_winex11_wglShareLists="$1"
+	enable_winex11_drv_Query_server_position="$1"
 	enable_winex11_drv_mouse_coorrds="$1"
 	enable_winhttp_System_Proxy_Autoconfig="$1"
 	enable_wininet_Cleanup="$1"
@@ -1204,6 +1205,9 @@ patch_enable ()
 		winex11-wglShareLists)
 			enable_winex11_wglShareLists="$2"
 			;;
+		winex11.drv-Query_server_position)
+			enable_winex11_drv_Query_server_position="$2"
+			;;
 		winex11.drv-mouse-coorrds)
 			enable_winex11_drv_mouse_coorrds="$2"
 			;;
@@ -7188,6 +7192,21 @@ if test "$enable_winex11_wglShareLists" -eq 1; then
 	) >> "$patchlist"
 fi
 
+# Patchset winex11.drv-Query_server_position
+# |
+# | This patchset fixes the following Wine bugs:
+# |   *	[#15346] winex11.drv: Query the X server for the actual rect of the window before unmapping it
+# |
+# | Modified files:
+# |   *	dlls/winex11.drv/window.c
+# |
+if test "$enable_winex11_drv_Query_server_position" -eq 1; then
+	patch_apply winex11.drv-Query_server_position/0001-winex11.drv-window-Query-the-X-server-for-the-actual.patch
+	(
+		printf '%s\n' '+    { "Gabriel Ivăncescu", "winex11.drv/window: Query the X server for the actual rect of the window before unmapping it.", 1 },';
+	) >> "$patchlist"
+fi
+
 # Patchset winex11.drv-mouse-coorrds
 # |
 # | This patchset fixes the following Wine bugs:
diff --git a/patches/winex11.drv-Query_server_position/0001-winex11.drv-window-Query-the-X-server-for-the-actual.patch b/patches/winex11.drv-Query_server_position/0001-winex11.drv-window-Query-the-X-server-for-the-actual.patch
new file mode 100644
index 00000000..b25db876
--- /dev/null
+++ b/patches/winex11.drv-Query_server_position/0001-winex11.drv-window-Query-the-X-server-for-the-actual.patch
@@ -0,0 +1,66 @@
+From 38d9b194e83b02f56d734da88396ac06ddb7af1f Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Gabriel=20Iv=C4=83ncescu?= <gabrielopcode@gmail.com>
+Date: Mon, 24 Dec 2018 14:26:57 +0200
+Subject: [PATCH] winex11.drv/window: Query the X server for the actual rect of
+ the window before unmapping it
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Some applications control their own position when they are being moved. This
+can become out of sync with the X server because certain WMs interfere with
+this on purpose.
+
+Thus we shouldn't just rely on our window rect when deciding whether to unmap
+a window (if it's out of the screen), but query the X server in this case
+as the last resort to make sure it really is outside and should be unmapped.
+
+Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=15346
+Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>
+---
+ dlls/winex11.drv/window.c | 22 +++++++++++++++++++++-
+ 1 file changed, 21 insertions(+), 1 deletion(-)
+
+diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
+index 97dee52..7f436ac 100644
+--- a/dlls/winex11.drv/window.c
++++ b/dlls/winex11.drv/window.c
+@@ -196,6 +196,25 @@ static BOOL has_owned_popups( HWND hwnd )
+     return result.found;
+ }
+ 
++static BOOL is_actual_window_rect_mapped(const struct x11drv_win_data *data)
++{
++    XWindowAttributes attr;
++    Window child;
++    RECT rect;
++    POINT pt;
++    int x, y;
++
++    /* Query the X server for the actual position of the window,
++       as some WMs tend to mess with it, so we need to make sure
++       we aren't unmapping the window wrongly with a bogus rect */
++    XTranslateCoordinates(data->display, data->whole_window, root_window, 0, 0, &x, &y, &child);
++    XGetWindowAttributes(data->display, data->whole_window, &attr);
++
++    pt = root_to_virtual_screen(x - attr.x, y - attr.y);
++    SetRect(&rect, pt.x, pt.y, pt.x + attr.width, pt.y + attr.height);
++    return is_window_rect_mapped(&rect);
++}
++
+ 
+ /***********************************************************************
+  *              alloc_win_data
+@@ -2400,7 +2419,8 @@ void CDECL X11DRV_WindowPosChanged( HWND hwnd, HWND insert_after, UINT swp_flags
+     {
+         if (((swp_flags & SWP_HIDEWINDOW) && !(new_style & WS_VISIBLE)) ||
+             (!event_type && !(new_style & WS_MINIMIZE) &&
+-             !is_window_rect_mapped( rectWindow ) && is_window_rect_mapped( &old_window_rect )))
++             !is_window_rect_mapped( rectWindow ) && is_window_rect_mapped( &old_window_rect ) &&
++             !is_actual_window_rect_mapped( data )))
+         {
+             release_win_data( data );
+             unmap_window( hwnd );
+-- 
+1.9.1
+
diff --git a/patches/winex11.drv-Query_server_position/definition b/patches/winex11.drv-Query_server_position/definition
new file mode 100644
index 00000000..022969e7
--- /dev/null
+++ b/patches/winex11.drv-Query_server_position/definition
@@ -0,0 +1 @@
+Fixes: [15346]  winex11.drv: Query the X server for the actual rect of the window before unmapping it