diff --git a/libs/backends/portaudio/winmmemidi_io.cc b/libs/backends/portaudio/winmmemidi_io.cc
index da7c8a2b8d..aa47d98488 100644
--- a/libs/backends/portaudio/winmmemidi_io.cc
+++ b/libs/backends/portaudio/winmmemidi_io.cc
@@ -18,6 +18,7 @@
 
 #include <windows.h>
 #include <mmsystem.h>
+#include <glibmm.h>
 
 #include <sstream>
 #include <set>