diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index cf89007693..bc9d3b345b 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -1120,10 +1120,10 @@ Session::butler_transport_work (bool have_process_lock)
 	bool finished = true;
 	PostTransportWork ptw = post_transport_work();
 #ifndef NDEBUG
-	uint64_t before;
+	uint64_t before = g_get_monotonic_time();
 #endif
 
-	DEBUG_TRACE (DEBUG::Transport, string_compose ("Butler transport work, todo = [%1] (0x%3%4%5) at %2\n", enum_2_string (ptw), (before = g_get_monotonic_time()), std::hex, ptw, std::dec));
+	DEBUG_TRACE (DEBUG::Transport, string_compose ("Butler transport work, todo = [%1] (0x%3%4%5) at %2\n", enum_2_string (ptw), before, std::hex, ptw, std::dec));
 
 	if (ptw & PostTransportAdjustPlaybackBuffering) {
 		/* need to prevent concurrency with ARDOUR::Reader::run(),