diff --git a/scrap2rtf/src/common_func.cpp b/scrap2rtf/src/common_func.cpp

index 07f96bf..9508460 100644

--- a/scrap2rtf/src/common_func.cpp

+++ b/scrap2rtf/src/common_func.cpp

@@ -17,6 +17,7 @@

    Andrey Ivnitsky <ivnitsky.a@gmail.com> */

 #include "common_func.h"

+#include <unistd.h>

 /* Extract file extension */

 const string ExtractFileExt(const string szFileName)