diff --git a/source/rpc_server/srv_lsa_nt.c b/source/rpc_server/srv_lsa_nt.c
index 1b42c5f141b..fb6538db39f 100644
--- a/source/rpc_server/srv_lsa_nt.c
+++ b/source/rpc_server/srv_lsa_nt.c
@@ -641,6 +641,11 @@ NTSTATUS _lsa_lookup_sids(pipes_struct *p, LSA_Q_LOOKUP_SIDS *q_u, LSA_R_LOOKUP_
 	LSA_TRANS_NAME_ENUM *names = NULL;
 	uint32 mapped_count = 0;
 
+	if (num_entries >  MAX_LOOKUP_SIDS) {
+		num_entries = MAX_LOOKUP_SIDS;
+		DEBUG(5,("_lsa_lookup_sids: truncating SID lookup list to %d\n", num_entries));
+	}
+		
 	ref = (DOM_R_REF *)talloc_zero(p->mem_ctx, sizeof(DOM_R_REF));
 	names = (LSA_TRANS_NAME_ENUM *)talloc_zero(p->mem_ctx, sizeof(LSA_TRANS_NAME_ENUM));