diff --git a/src/backend.c b/src/backend.c
index 35e6f781d..490dc1f28 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -640,14 +640,25 @@ int assign_server(struct stream *s)
 			}
 		}
 	}
-	if (s->be->lbprm.algo & BE_LB_KIND) {
 
+	if (s->be->lbprm.algo & BE_LB_KIND) {
 		/* we must check if we have at least one server available */
 		if (!s->be->lbprm.tot_weight) {
 			err = SRV_STATUS_NOSRV;
 			goto out;
 		}
 
+		/* if there's some queue on the backend, with certain algos we
+		 * know it's because all servers are full.
+		 */
+		if (s->be->nbpend &&
+		    (((s->be->lbprm.algo & BE_LB_KIND) == BE_LB_KIND_CB) || // conn-based: leastconn & first
+		     ((s->be->lbprm.algo & (BE_LB_KIND|BE_LB_NEED|BE_LB_PARM)) == BE_LB_ALGO_RR) ||   // roundrobin
+		     ((s->be->lbprm.algo & (BE_LB_KIND|BE_LB_NEED|BE_LB_PARM)) == BE_LB_ALGO_SRR))) { // static-rr
+			err = SRV_STATUS_FULL;
+			goto out;
+		}
+
 		/* First check whether we need to fetch some data or simply call
 		 * the LB lookup function. Only the hashing functions will need
 		 * some input data in fact, and will support multiple algorithms.