diff --git a/src/null_init.c b/src/null_init.c
index 7236c98c..8d93e944 100644
--- a/src/null_init.c
+++ b/src/null_init.c
@@ -71,6 +71,7 @@ GLFWbool _glfwConnectNull(int platformID, _GLFWplatform* platform)
         _glfwGetGammaRampNull,
         _glfwSetGammaRampNull,
         _glfwCreateWindowNull,
+        _glfwAttachWindowNull,
         _glfwDestroyWindowNull,
         _glfwSetWindowTitleNull,
         _glfwSetWindowIconNull,
@@ -263,4 +264,3 @@ void _glfwTerminateNull(void)
     _glfwTerminateOSMesa();
     _glfwTerminateEGL();
 }
-
diff --git a/src/null_platform.h b/src/null_platform.h
index 6d900111..5d0f4b95 100644
--- a/src/null_platform.h
+++ b/src/null_platform.h
@@ -210,6 +210,7 @@ GLFWbool _glfwGetGammaRampNull(_GLFWmonitor* monitor, GLFWgammaramp* ramp);
 void _glfwSetGammaRampNull(_GLFWmonitor* monitor, const GLFWgammaramp* ramp);
 
 GLFWbool _glfwCreateWindowNull(_GLFWwindow* window, const _GLFWwndconfig* wndconfig, const _GLFWctxconfig* ctxconfig, const _GLFWfbconfig* fbconfig);
+GLFWbool _glfwAttachWindowNull(_GLFWwindow* window, intptr_t native, const _GLFWwndconfig* wndconfig, const _GLFWctxconfig* ctxconfig, const _GLFWfbconfig* fbconfig);
 void _glfwDestroyWindowNull(_GLFWwindow* window);
 void _glfwSetWindowTitleNull(_GLFWwindow* window, const char* title);
 void _glfwSetWindowIconNull(_GLFWwindow* window, int count, const GLFWimage* images);
@@ -270,4 +271,3 @@ GLFWbool _glfwGetPhysicalDevicePresentationSupportNull(VkInstance instance, VkPh
 VkResult _glfwCreateWindowSurfaceNull(VkInstance instance, _GLFWwindow* window, const VkAllocationCallbacks* allocator, VkSurfaceKHR* surface);
 
 void _glfwPollMonitorsNull(void);
-
diff --git a/src/null_window.c b/src/null_window.c
index e0bbb3b6..cb22d715 100644
--- a/src/null_window.c
+++ b/src/null_window.c
@@ -106,6 +106,39 @@ static int createNativeWindow(_GLFWwindow* window,
 
     return GLFW_TRUE;
 }
+static int attachNativeWindow(_GLFWwindow* window,
+                              intptr_t native,
+                              const _GLFWwndconfig* wndconfig,
+                              const _GLFWfbconfig* fbconfig)
+{
+    if (window->monitor)
+        fitToMonitor(window);
+    else
+    {
+        if (wndconfig->xpos == GLFW_ANY_POSITION && wndconfig->ypos == GLFW_ANY_POSITION)
+        {
+            window->null.xpos = 17;
+            window->null.ypos = 17;
+        }
+        else
+        {
+            window->null.xpos = wndconfig->xpos;
+            window->null.ypos = wndconfig->ypos;
+        }
+
+        window->null.width = wndconfig->width;
+        window->null.height = wndconfig->height;
+    }
+
+    window->null.visible = wndconfig->visible;
+    window->null.decorated = wndconfig->decorated;
+    window->null.maximized = wndconfig->maximized;
+    window->null.floating = wndconfig->floating;
+    window->null.transparent = fbconfig->transparent;
+    window->null.opacity = 1.f;
+
+    return GLFW_TRUE;
+}
 
 
 //////////////////////////////////////////////////////////////////////////
@@ -166,6 +199,61 @@ GLFWbool _glfwCreateWindowNull(_GLFWwindow* window,
 
     return GLFW_TRUE;
 }
+GLFWbool _glfwAttachWindowNull(_GLFWwindow* window,
+                               intptr_t native,
+                               const _GLFWwndconfig* wndconfig,
+                               const _GLFWctxconfig* ctxconfig,
+                               const _GLFWfbconfig* fbconfig)
+{
+    if (!attachNativeWindow(window, native, wndconfig, fbconfig))
+        return GLFW_FALSE;
+
+    if (ctxconfig->client != GLFW_NO_API)
+    {
+        if (ctxconfig->source == GLFW_NATIVE_CONTEXT_API ||
+            ctxconfig->source == GLFW_OSMESA_CONTEXT_API)
+        {
+            if (!_glfwInitOSMesa())
+                return GLFW_FALSE;
+            if (!_glfwCreateContextOSMesa(window, ctxconfig, fbconfig))
+                return GLFW_FALSE;
+        }
+        else if (ctxconfig->source == GLFW_EGL_CONTEXT_API)
+        {
+            if (!_glfwInitEGL())
+                return GLFW_FALSE;
+            if (!_glfwCreateContextEGL(window, ctxconfig, fbconfig))
+                return GLFW_FALSE;
+        }
+
+        if (!_glfwRefreshContextAttribs(window, ctxconfig))
+            return GLFW_FALSE;
+    }
+
+    if (wndconfig->mousePassthrough)
+        _glfwSetWindowMousePassthroughNull(window, GLFW_TRUE);
+
+    if (window->monitor)
+    {
+        _glfwShowWindowNull(window);
+        _glfwFocusWindowNull(window);
+        acquireMonitor(window);
+
+        if (wndconfig->centerCursor)
+            _glfwCenterCursorInContentArea(window);
+    }
+    else
+    {
+        if (wndconfig->visible)
+        {
+            _glfwShowWindowNull(window);
+            if (wndconfig->focused)
+                _glfwFocusWindowNull(window);
+        }
+    }
+
+    return GLFW_TRUE;
+}
 
 void _glfwDestroyWindowNull(_GLFWwindow* window)
 {
@@ -717,4 +805,3 @@ VkResult _glfwCreateWindowSurfaceNull(VkInstance instance,
     // This seems like the most appropriate error to return here
     return VK_ERROR_EXTENSION_NOT_PRESENT;
 }
-
diff --git a/src/x11_init.c b/src/x11_init.c
index a0100f2f..fe2a9f62 100644
--- a/src/x11_init.c
+++ b/src/x11_init.c
@@ -1206,6 +1206,7 @@ GLFWbool _glfwConnectX11(int platformID, _GLFWplatform* platform)
         _glfwGetGammaRampX11,
         _glfwSetGammaRampX11,
         _glfwCreateWindowX11,
+        _glfwAttachWindowX11,
         _glfwDestroyWindowX11,
         _glfwSetWindowTitleX11,
         _glfwSetWindowIconX11,
@@ -1655,4 +1656,3 @@ void _glfwTerminateX11(void)
 }
 
 #endif // _GLFW_X11
-
diff --git a/src/x11_platform.h b/src/x11_platform.h
index cdea3957..fc7cdae9 100644
--- a/src/x11_platform.h
+++ b/src/x11_platform.h
@@ -902,6 +902,7 @@ int _glfwInitX11(void);
 void _glfwTerminateX11(void);
 
 GLFWbool _glfwCreateWindowX11(_GLFWwindow* window, const _GLFWwndconfig* wndconfig, const _GLFWctxconfig* ctxconfig, const _GLFWfbconfig* fbconfig);
+GLFWbool _glfwAttachWindowX11(_GLFWwindow* window, intptr_t native, const _GLFWwndconfig* wndconfig, const _GLFWctxconfig* ctxconfig, const _GLFWfbconfig* fbconfig);
 void _glfwDestroyWindowX11(_GLFWwindow* window);
 void _glfwSetWindowTitleX11(_GLFWwindow* window, const char* title);
 void _glfwSetWindowIconX11(_GLFWwindow* window, int count, const GLFWimage* images);
@@ -1001,4 +1002,3 @@ GLFWbool _glfwChooseVisualGLX(const _GLFWwndconfig* wndconfig,
                               const _GLFWctxconfig* ctxconfig,
                               const _GLFWfbconfig* fbconfig,
                               Visual** visual, int* depth);
-
diff --git a/src/x11_window.c b/src/x11_window.c
index 7da9b965..1df4f8c8 100644
--- a/src/x11_window.c
+++ b/src/x11_window.c
@@ -2044,6 +2044,15 @@ GLFWbool _glfwCreateWindowX11(_GLFWwindow* window,
     return GLFW_TRUE;
 }
 
+GLFWbool _glfwCreateWindowX11(_GLFWwindow* window,
+                              intptr_t native,
+                              const _GLFWwndconfig* wndconfig,
+                              const _GLFWctxconfig* ctxconfig,
+                              const _GLFWfbconfig* fbconfig) {
+    _glfwInputError(GLFW_PLATFORM_ERROR, "X11 window attachment is not implemented");
+    return GLFW_FALSE;
+}
+
 void _glfwDestroyWindowX11(_GLFWwindow* window)
 {
     if (_glfw.x11.disabledCursorWindow == window)
@@ -3352,4 +3361,3 @@ GLFWAPI const char* glfwGetX11SelectionString(void)
 }
 
 #endif // _GLFW_X11
-