diff --git a/src/internal.h b/src/internal.h
index 8eda20e56..fd4f976b9 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -710,7 +710,6 @@ void _glfwInputWindowIconify(_GLFWwindow* window, GLFWbool iconified);
 void _glfwInputWindowMaximize(_GLFWwindow* window, GLFWbool maximized);
 void _glfwInputWindowDamage(_GLFWwindow* window);
 void _glfwInputWindowCloseRequest(_GLFWwindow* window);
-void _glfwInputWindowMonitor(_GLFWwindow* window, _GLFWmonitor* monitor);
 
 void _glfwInputKey(_GLFWwindow* window,
                    int key, int scancode, int action, int mods);