diff --git a/lib/irrlicht/source/Irrlicht/CIrrDeviceLinux.cpp b/lib/irrlicht/source/Irrlicht/CIrrDeviceLinux.cpp
index d646665cd..6846e7912 100644
--- a/lib/irrlicht/source/Irrlicht/CIrrDeviceLinux.cpp
+++ b/lib/irrlicht/source/Irrlicht/CIrrDeviceLinux.cpp
@@ -11,6 +11,7 @@ extern bool GLContextDebugBit;
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <sys/utsname.h>
 #include <time.h>
 #include "IEventReceiver.h"