diff --git a/src/win32/win32_window.c b/src/win32/win32_window.c
index 7d202ba0..8ac59203 100644
--- a/src/win32/win32_window.c
+++ b/src/win32/win32_window.c
@@ -1018,7 +1018,7 @@ static void initWGLExtensions(_GLFWwindow* window)
 
     if (_glfwPlatformExtensionSupported("WGL_EXT_swap_control"))
     {
-        window->WGL.SwapIntervalEXT = (PFNWGLSWAPINTERVALEXT)
+        window->WGL.SwapIntervalEXT = (PFNWGLSWAPINTERVALEXTPROC)
             wglGetProcAddress("wglSwapIntervalEXT");
 
         if (window->WGL.SwapIntervalEXT)