diff --git a/libs/backends/jack/jack_portengine.cc b/libs/backends/jack/jack_portengine.cc
index 942da6b26b..0074732953 100644
--- a/libs/backends/jack/jack_portengine.cc
+++ b/libs/backends/jack/jack_portengine.cc
@@ -19,6 +19,7 @@
 
 #include <string.h>
 #include <stdint.h>
+#include <errno.h>
 
 #include "pbd/error.h"