Index: uspace/app/trace/proto.c
===================================================================
--- uspace/app/trace/proto.c	(revision 062d9000625057300f609429080872d6492b542e)
+++ uspace/app/trace/proto.c	(revision 33c29521d96b892e096419a2fd8beb867e2596f6)
@@ -79,6 +79,6 @@
 	.key_hash = srv_proto_key_hash,
 	.key_equal = srv_proto_key_equal,
-	.equal = 0,
-	.remove_callback = 0
+	.equal = NULL,
+	.remove_callback = NULL
 };
 
@@ -105,6 +105,6 @@
 	.key_hash = method_oper_key_hash,
 	.key_equal = method_oper_key_equal,
-	.equal = 0,
-	.remove_callback = 0
+	.equal = NULL,
+	.remove_callback = NULL
 };