diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 9a82192175..49a0eed559 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -694,7 +694,7 @@ Session::remove_state (string snapshot_name)
 void
 Session::jack_session_event (jack_session_event_t * event)
 {
-        char timebuf[128];
+        char timebuf[128], *tmp;
         time_t n;
         struct tm local_time;
 
@@ -702,6 +702,8 @@ Session::jack_session_event (jack_session_event_t * event)
         localtime_r (&n, &local_time);
         strftime (timebuf, sizeof(timebuf), "JS_%FT%T", &local_time);
 
+        while ((tmp = strchr(timebuf, ':'))) { *tmp = '.'; }
+
         if (event->type == JackSessionSaveTemplate)
         {
                 if (save_template( timebuf )) {