diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 6b667d01..46bb8133 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -6201,7 +6201,7 @@ GLFWAPI GLFWglproc glfwGetProcAddress(const char* procname);
 GLFWAPI int glfwVulkanSupported(void);
 
 #ifdef ZD_GLFW_FORK
-typedef int(*glfwMouseDragCheckFn)();
+typedef int(*glfwMouseDragCheckFn)(GLFWwindow* window);
 GLFWAPI void SetMouseDragCheckFn(glfwMouseDragCheckFn function);
 GLFWAPI void glfwGetBorder(int* border);
 #endif
diff --git a/src/win32_window.c b/src/win32_window.c
index da55c04b..ab8f2cba 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -82,7 +82,7 @@ void adjust_maximized_client_rect(HWND window, NCCALCSIZE_PARAMS* params) {
     params->rgrc[0] = monitor_info.rcWork;
 }
 
-LRESULT hit_test(HWND handle, POINT cursor) {
+LRESULT hit_test(_GLFWwindow* wnd, HWND handle, POINT cursor) {
     // identify borders and corners to allow resizing the window.
     // Note: On Windows 10, windows behave differently and
     // allow resizing outside the visible window frame.
@@ -96,7 +96,7 @@ LRESULT hit_test(HWND handle, POINT cursor) {
         return HTNOWHERE;
     }
 
-    const int64_t drag = checkDragFunction ? (checkDragFunction() ? HTCAPTION : HTCLIENT) : HTCLIENT;
+    const int64_t drag = checkDragFunction ? (checkDragFunction((GLFWwindow*) wnd) ? HTCAPTION : HTCLIENT) : HTCLIENT;
     
     enum region_mask {
         client = 0b0000,
@@ -665,7 +665,7 @@ static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM l
                 POINT cursor;
                 cursor.x = GET_X_LPARAM(lParam);
                 cursor.y = GET_Y_LPARAM(lParam);
-                return hit_test(hWnd, cursor);
+                return hit_test(window, hWnd, cursor);
             }
             break;
         }