diff --git a/lib/krb5/krbhst.c b/lib/krb5/krbhst.c
index 6d2f65356..8b4ad0726 100644
--- a/lib/krb5/krbhst.c
+++ b/lib/krb5/krbhst.c
@@ -104,7 +104,9 @@ srv_find_realm(krb5_context context, krb5_krbhst_info ***res, int *count,
     for(num_srv = 0, rr = r->head; rr; rr = rr->next) 
 	if(rr->type == T_SRV) {
 	    krb5_krbhst_info *hi;
-	    hi = calloc(1, sizeof(*hi) + strlen(rr->u.srv->target));
+	    size_t len = strlen(rr->u.srv->target);
+
+	    hi = calloc(1, sizeof(*hi) + len);
 	    if(hi == NULL) {
 		dns_free_data(r);
 		while(--num_srv >= 0)