diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -630,8 +630,8 @@
 		/* Reference prefix */
 		ia->ia6_ndpr = pr;
 		pr->ndpr_addrcnt++;
-	} else
-		nd6_prefix_rele(pr);
+	}
+	nd6_prefix_rele(pr);
 
 	return 0;
 }