diff --git a/filter/data.h b/filter/data.h
index 28c7a888..ecbc3d4f 100644
--- a/filter/data.h
+++ b/filter/data.h
@@ -173,6 +173,7 @@ struct f_trie
   u8 zero;
   s8 ipv4;				/* -1 for undefined / empty */
   u16 data_size;			/* Additional data for each trie node */
+  u32 prefix_count;			/* Works only for restricted tries (pxlen == l == h) */
   struct f_trie_node root;		/* Root trie node */
 };
 
diff --git a/filter/trie.c b/filter/trie.c
index 50d349fe..57a0cc2a 100644
--- a/filter/trie.c
+++ b/filter/trie.c
@@ -247,6 +247,7 @@ trie_amask_to_local(ip_addr px, ip_addr amask, uint nlen)
 #define GET_ADDR(N,F,X) ((X) ? ipt_from_ip4((N)->v4.F) : ipa_from_ip6((N)->v6.F))
 #define SET_ADDR(N,F,X,V) ({ if (X) (N)->v4.F =ipt_to_ip4(V); else (N)->v6.F =ipa_to_ip6(V); })
 
+#define GET_LOCAL(N,X) ((X) ? (N)->v4.local : (N)->v6.local)
 #define ADD_LOCAL(N,X,V) ({ uint v_ = (V); if (X) (N)->v4.local |= v_; else (N)->v6.local |= v_; })
 
 #define GET_CHILD(N,X,I) ((X) ? (struct f_trie_node *) (N)->v4.c[I] : (struct f_trie_node *) (N)->v6.c[I])
@@ -299,6 +300,7 @@ trie_add_node(struct f_trie *t, uint plen, ip_addr px, uint local, uint l, uint
 	  attach_node(o, b, v4);
 	  attach_node(b, n, v4);
 	  attach_node(b, a, v4);
+	  t->prefix_count++;
 
 	  DBG("Case 1\n");
 	  return a;
@@ -312,6 +314,7 @@ trie_add_node(struct f_trie *t, uint plen, ip_addr px, uint local, uint l, uint
 	  struct f_trie_node *a = new_node(t, plen, local, paddr, pmask, amask);
 	  attach_node(o, a, v4);
 	  attach_node(a, n, v4);
+	  t->prefix_count++;
 
 	  DBG("Case 2\n");
 	  return a;
@@ -322,6 +325,10 @@ trie_add_node(struct f_trie *t, uint plen, ip_addr px, uint local, uint l, uint
 	  /* We already found added node in trie. Just update accept and local mask */
 	  accept = ipa_or(accept, amask);
 	  SET_ADDR(n, accept, v4, accept);
+
+	  if ((GET_LOCAL(n, v4) & local) != local)
+	    t->prefix_count++;
+
 	  ADD_LOCAL(n, v4, local);
 
 	  DBG("Case 3\n");
@@ -343,6 +350,7 @@ trie_add_node(struct f_trie *t, uint plen, ip_addr px, uint local, uint l, uint
   /* We add new tail node 'a' after node 'o' */
   struct f_trie_node *a = new_node(t, plen, local, paddr, pmask, amask);
   attach_node(o, a, v4);
+  t->prefix_count++;
 
   DBG("Case 4\n");
   return a;
diff --git a/filter/trie_test.c b/filter/trie_test.c
index eee48284..c7775006 100644
--- a/filter/trie_test.c
+++ b/filter/trie_test.c
@@ -687,6 +687,7 @@ t_trie_walk(void)
     bt_debug("Full walk (round %d, %d nets)\n", round, num);
 
     pos = 0;
+    uint pxc = 0;
     TRIE_WALK(trie, net, NULL)
     {
       log_networks(&net, &pxset[pos].net);
@@ -697,10 +698,12 @@ t_trie_walk(void)
 	pos++;
 
       pos++;
+      pxc++;
     }
     TRIE_WALK_END;
 
     bt_assert(pos == num);
+    bt_assert(pxc == trie->prefix_count);
     bt_debug("Full walk done\n");