diff --git a/lib/altsvc.c b/lib/altsvc.c
index 2d46b95c90..b5fb65fde1 100644
--- a/lib/altsvc.c
+++ b/lib/altsvc.c
@@ -106,9 +106,11 @@ static struct altsvc *altsvc_createid(const char *srchost,
   dlen = strlen(dsthost);
   DEBUGASSERT(hlen);
   DEBUGASSERT(dlen);
-  if(!hlen || !dlen)
+  if(!hlen || !dlen) {
     /* bad input */
+    free(as);
     return NULL;
+  }
   if((hlen > 2) && srchost[0] == '[') {
     /* IPv6 address, strip off brackets */
     srchost++;