diff --git a/gst-libs/gst/gl/gstglwindow.c b/gst-libs/gst/gl/gstglwindow.c
index 9281a6e6d4..497474d176 100644
--- a/gst-libs/gst/gl/gstglwindow.c
+++ b/gst-libs/gst/gl/gstglwindow.c
@@ -771,15 +771,15 @@ gst_gl_dummy_window_new (void)
 }
 
 void
-gst_gl_window_send_key_event (GstGLWindow * window, char *event_type,
-    char *key_str)
+gst_gl_window_send_key_event (GstGLWindow * window, const char *event_type,
+    const char *key_str)
 {
   g_signal_emit (window, gst_gl_window_signals[EVENT_KEY_SIGNAL], 0,
       event_type, key_str);
 }
 
 void
-gst_gl_window_send_mouse_event (GstGLWindow * window, char *event_type,
+gst_gl_window_send_mouse_event (GstGLWindow * window, const char *event_type,
     int button, double posx, double posy)
 {
   g_signal_emit (window, gst_gl_window_signals[EVENT_MOUSE_SIGNAL], 0,
diff --git a/gst-libs/gst/gl/gstglwindow.h b/gst-libs/gst/gl/gstglwindow.h
index 0b1941f834..ce5cba9053 100644
--- a/gst-libs/gst/gl/gstglwindow.h
+++ b/gst-libs/gst/gl/gstglwindow.h
@@ -153,9 +153,9 @@ GstGLContext * gst_gl_window_get_context (GstGLWindow *window);
 
 gboolean gst_gl_window_is_running (GstGLWindow *window);
 
-void gst_gl_window_send_key_event(GstGLWindow * window, char * event_type,
-    char * key_str);
-void gst_gl_window_send_mouse_event(GstGLWindow * window, char *
+void gst_gl_window_send_key_event(GstGLWindow * window, const char * event_type,
+    const char * key_str);
+void gst_gl_window_send_mouse_event(GstGLWindow * window, const char *
     event_type, int button, double posx, double posy);
 
 GST_DEBUG_CATEGORY_EXTERN (gst_gl_window_debug);