diff --git a/include/SDL3/SDL_hints.h b/include/SDL3/SDL_hints.h
index 2f01f09881..00c185b3c6 100644
--- a/include/SDL3/SDL_hints.h
+++ b/include/SDL3/SDL_hints.h
@@ -4128,6 +4128,31 @@ extern "C" {
  */
 #define SDL_HINT_VIDEO_WIN_D3DCOMPILER "SDL_VIDEO_WIN_D3DCOMPILER"
 
+/**
+ * A variable controlling whether the X Synchronization Extension is enabled.
+ *
+ * If set, this can result in smoother window resizing when rendering using
+ * OpenGL, however, there are some conditions:
+ *
+ *  - It is only activated on windows created with the `SDL_WINDOW_OPENGL` flag
+ *    (windows using an SDL OpenGL renderer have this automatically set).
+ *  - When activated, presentation must be done with `SDL_GL_SwapWindow()`
+ *    (`SDL_RenderPresent()` calls this internally for OpenGL renderers as well).
+ *
+ * Enabling this and presenting via an external mechanism will result in sync
+ * requests not being acked, and hangs and other odd window behavior may result.
+ *
+ * The variable can be set to the following values:
+ *
+ * - "0": The X Synchronization Extension is disabled. (default)
+ * - "1": The X Synchronization Extension is enabled.
+ *
+ * This hint should be set before creating a window.
+ *
+ * \since This hint is available since SDL 3.4.10.
+ */
+#define SDL_HINT_VIDEO_X11_ENABLE_XSYNC_EXT "SDL_VIDEO_X11_ENABLE_XSYNC_EXT"
+
 /**
  * A variable controlling whether SDL should call XSelectInput() to enable
  * input events on X11 windows wrapped by SDL windows.
diff --git a/src/video/x11/SDL_x11window.c b/src/video/x11/SDL_x11window.c
index 4a68287cc2..b1f982a32e 100644
--- a/src/video/x11/SDL_x11window.c
+++ b/src/video/x11/SDL_x11window.c
@@ -585,7 +585,8 @@ bool X11_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_Properties
     }
 
     const bool force_override_redirect = SDL_GetHintBoolean(SDL_HINT_X11_FORCE_OVERRIDE_REDIRECT, false);
-    const bool use_resize_sync = !!(window->flags & SDL_WINDOW_OPENGL); // Doesn't work well with Vulkan
+    const bool use_resize_sync = SDL_GetHintBoolean(SDL_HINT_VIDEO_X11_ENABLE_XSYNC_EXT, false) &&
+                                 (window->flags & SDL_WINDOW_OPENGL) != 0; // Doesn't work well with Vulkan
     SDL_WindowData *windowdata;
     Display *display = data->display;
     int screen = displaydata->screen;