diff --git a/src/supplicant/nm-supplicant-interface.c b/src/supplicant/nm-supplicant-interface.c
index 12d21aba44..8649b24efe 100644
--- a/src/supplicant/nm-supplicant-interface.c
+++ b/src/supplicant/nm-supplicant-interface.c
@@ -2981,5 +2981,5 @@ nm_supplicant_interface_class_init (NMSupplicantInterfaceClass *klass)
 	                  G_SIGNAL_RUN_LAST,
 	                  0,
 	                  NULL, NULL, NULL,
-	                  G_TYPE_NONE, 1, G_TYPE_VARIANT);
+	                  G_TYPE_NONE, 1, G_TYPE_STRING);
 }