diff --git a/nest/a-path.c b/nest/a-path.c
index ad9780c7..7ac50e1b 100644
--- a/nest/a-path.c
+++ b/nest/a-path.c
@@ -298,6 +298,9 @@ as_path_match(struct adata *path, struct f_path_mask *mask)
   u8 *next;
   u32 as;
 
+  if (!mask)
+    return ! path->length;
+
   asterisk = mask->any;
   if (asterisk)
     { mask = mask->next; if (!mask) return 1; }