diff --git a/jam/fileunix.c b/jam/fileunix.c
index d4f3427f45..1fb6f63508 100644
--- a/jam/fileunix.c
+++ b/jam/fileunix.c
@@ -58,7 +58,7 @@
 # define STRUCT_DIRENT struct dirent 
 # endif
 
-# ifdef __CYGWIN__
+# if defined(__CYGWIN__) || defined(unix)
 # include <unistd.h>
 # endif