diff --git a/src/shell-global.c b/src/shell-global.c
index 2b6eb8f65..480b2fe4d 100644
--- a/src/shell-global.c
+++ b/src/shell-global.c
@@ -1583,7 +1583,7 @@ shell_global_get_current_time (ShellGlobal *global)
  */
 GAppLaunchContext *
 shell_global_create_app_launch_context (ShellGlobal *global,
-                                        int          timestamp,
+                                        guint32      timestamp,
                                         int          workspace)
 {
   GdkAppLaunchContext *context;
diff --git a/src/shell-global.h b/src/shell-global.h
index c043f4714..47c441553 100644
--- a/src/shell-global.h
+++ b/src/shell-global.h
@@ -71,7 +71,7 @@ void     shell_global_sync_pointer              (ShellGlobal  *global);
 
 GAppLaunchContext *
          shell_global_create_app_launch_context (ShellGlobal  *global,
-                                                 int           timestamp,
+                                                 guint32       timestamp,
                                                  int           workspace);
 
 void     shell_global_play_theme_sound          (ShellGlobal *global,