diff --git a/src/eval.c b/src/eval.c
index 1637e6d..8a62fa8 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -14141,8 +14141,8 @@
 	    }
 	    else
 	    {
-		list_append_string(rettv->vval.v_list, NUL, -1);
-		list_append_string(rettv->vval.v_list, NUL, -1);
+		list_append_string(rettv->vval.v_list, NULL, -1);
+		list_append_string(rettv->vval.v_list, NULL, -1);
 	    }
 	}
 #endif