diff --git a/isisd/isis_adjacency.c b/isisd/isis_adjacency.c
index c7ab83b..8afabed 100644
--- a/isisd/isis_adjacency.c
+++ b/isisd/isis_adjacency.c
@@ -507,6 +507,11 @@
   struct isis_adjacency *adj;
   struct listnode *node;
 
+  if (adjdb == NULL) {
+    zlog_warn ("isis_adj_build_up_list(): adjacency DB is empty");
+    return;
+  }
+
   if (!list)
     {
       zlog_warn ("isis_adj_build_up_list(): NULL list");