diff --git a/gtk2_ardour/midi_tracer.cc b/gtk2_ardour/midi_tracer.cc
index 70d7c24da6..1fc50c103f 100644
--- a/gtk2_ardour/midi_tracer.cc
+++ b/gtk2_ardour/midi_tracer.cc
@@ -23,6 +23,8 @@
 #include <sys/time.h>
 #include <time.h>
 
+#include "pbd/localtime_r.h"
+
 #include "midi++/parser.h"
 #include "midi++/manager.h"