diff --git a/libs/backends/portaudio/winmmemidi_input_device.cc b/libs/backends/portaudio/winmmemidi_input_device.cc
index d606b1110c..929f099834 100644
--- a/libs/backends/portaudio/winmmemidi_input_device.cc
+++ b/libs/backends/portaudio/winmmemidi_input_device.cc
@@ -24,6 +24,7 @@
 #include <cmath>
 
 #include "pbd/compose.h"
+#include "pbd/microseconds.h"
 #include "pbd/windows_timer_utils.h"
 #include "pbd/windows_mmcss.h"