diff --git a/gio/gsimpleasyncresult.c b/gio/gsimpleasyncresult.c
index 0c1604939..e17793714 100644
--- a/gio/gsimpleasyncresult.c
+++ b/gio/gsimpleasyncresult.c
@@ -486,7 +486,7 @@ g_simple_async_result_get_op_res_gboolean (GSimpleAsyncResult *simple)
  **/
 void
 g_simple_async_result_set_from_error (GSimpleAsyncResult *simple,
-                                      GError             *error)
+                                      const GError       *error)
 {
   g_return_if_fail (G_IS_SIMPLE_ASYNC_RESULT (simple));
   g_return_if_fail (error != NULL);
diff --git a/gio/gsimpleasyncresult.h b/gio/gsimpleasyncresult.h
index 7259a9731..073796cbe 100644
--- a/gio/gsimpleasyncresult.h
+++ b/gio/gsimpleasyncresult.h
@@ -89,7 +89,7 @@ void                g_simple_async_result_run_in_thread    (GSimpleAsyncResult
 							    int                      io_priority,
 							    GCancellable            *cancellable);
 void                g_simple_async_result_set_from_error   (GSimpleAsyncResult      *simple,
-							    GError                  *error);
+							    const GError            *error);
 gboolean            g_simple_async_result_propagate_error  (GSimpleAsyncResult      *simple,
 							    GError                 **dest);
 void                g_simple_async_result_set_error        (GSimpleAsyncResult      *simple,