diff --git a/libs/backends/portaudio/winmmemidi_output_device.cc b/libs/backends/portaudio/winmmemidi_output_device.cc
index d26925b8a3..316afce614 100644
--- a/libs/backends/portaudio/winmmemidi_output_device.cc
+++ b/libs/backends/portaudio/winmmemidi_output_device.cc
@@ -24,6 +24,7 @@
 
 #include "pbd/debug.h"
 #include "pbd/compose.h"
+#include "pbd/microseconds.h"
 #include "pbd/pthread_utils.h"
 #include "pbd/windows_timer_utils.h"
 #include "pbd/windows_mmcss.h"