diff --git a/Common/CommonFuncs.h b/Common/CommonFuncs.h
index f7f6f28e81..cae36a2cc7 100644
--- a/Common/CommonFuncs.h
+++ b/Common/CommonFuncs.h
@@ -27,6 +27,7 @@ template<> struct CompileTimeAssert<true> {};
 
 #ifndef _WIN32
 
+#include <unistd.h>
 #include <errno.h>
 #ifdef __linux__
 #include <byteswap.h>