diff --git a/lib/utils/mu-utils.cc b/lib/utils/mu-utils.cc
index 1c02ed06..a2772578 100644
--- a/lib/utils/mu-utils.cc
+++ b/lib/utils/mu-utils.cc
@@ -28,6 +28,7 @@
 #define GNU_SOURCE
 #include <stdio.h>
 #include <stdint.h>
+#include <unistd.h>
 
 #include <string.h>
 #include <iostream>