diff --git a/src/tools/map_extractor/System.cpp b/src/tools/map_extractor/System.cpp
index f474925313e..d0342717324 100644
--- a/src/tools/map_extractor/System.cpp
+++ b/src/tools/map_extractor/System.cpp
@@ -9,6 +9,7 @@
 #include "direct.h"
 #else
 #include <sys/stat.h>
+#include <unistd.h>
 #endif
 
 #include "dbcfile.h"