Index: uspace/app/trace/proto.c
===================================================================
--- uspace/app/trace/proto.c	(revision 062d9000625057300f609429080872d6492b542e)
+++ uspace/app/trace/proto.c	(revision 22dfd380be327d91cff2394cd2f3d9143dd73a90)
@@ -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
 };