diff --git a/src/network/transportsender.cc b/src/network/transportsender.cc
index 9da8f50..9d04b64 100644
--- a/src/network/transportsender.cc
+++ b/src/network/transportsender.cc
@@ -152,15 +152,14 @@ void TransportSender<MyState>::tick( void )
 
   attempt_prospective_resend_optimization( diff );
 
-  /* verify diff has round-trip identity (modulo Unicode fallback rendering) */
-  /*
-  MyState newstate( assumed_receiver_state->state );
-  newstate.apply_string( diff );
-  if ( current_state.compare( newstate ) ) {
-    fprintf( stderr, "Diff: %s\n", diff.c_str() );
+  if ( verbose ) {
+    /* verify diff has round-trip identity (modulo Unicode fallback rendering) */
+    MyState newstate( assumed_receiver_state->state );
+    newstate.apply_string( diff );
+    if ( current_state.compare( newstate ) ) {
+      fprintf( stderr, "Diff: %s\n", diff.c_str() );
+    }
   }
-  */
-
 
   if ( diff.empty() && (now >= next_ack_time) ) {
     send_empty_ack();