diff --git a/src/fe-gtk/notifications/notification-dummy.c b/src/fe-gtk/notifications/notification-dummy.c
index 022443bf..9aa7d19c 100644
--- a/src/fe-gtk/notifications/notification-dummy.c
+++ b/src/fe-gtk/notifications/notification-dummy.c
@@ -22,7 +22,7 @@ notification_backend_show (const char *title, const char *text)
 }
 
 int
-notification_backend_init (void)
+notification_backend_init (const char **error)
 {
 	return 0;
 }
diff --git a/src/fe-gtk/notifications/notification-libnotify.c b/src/fe-gtk/notifications/notification-libnotify.c
index 91148377..aa2d087a 100644
--- a/src/fe-gtk/notifications/notification-libnotify.c
+++ b/src/fe-gtk/notifications/notification-libnotify.c
@@ -53,7 +53,7 @@ notification_backend_show (const char *title, const char *text)
 }
 
 int
-notification_backend_init (void)
+notification_backend_init (const char **error)
 {
 	GList* server_caps;
 
diff --git a/src/fe-gtk/notifications/notification-osx.m b/src/fe-gtk/notifications/notification-osx.m
index c9ad72d0..75aaf777 100644
--- a/src/fe-gtk/notifications/notification-osx.m
+++ b/src/fe-gtk/notifications/notification-osx.m
@@ -37,7 +37,7 @@ notification_backend_show (const char *title, const char *text)
 }
 
 int
-notification_backend_init (void)
+notification_backend_init (const char **error)
 {
 	return 1;
 }