diff --git a/compat/posix-shims/unistd.h b/compat/posix-shims/unistd.h
index e01a73d..ab717a7 100644
--- a/compat/posix-shims/unistd.h
+++ b/compat/posix-shims/unistd.h
@@ -18,7 +18,7 @@
    These may be OR'd together.  */
 #define R_OK    4       /* Test for read permission.  */
 #define W_OK    2       /* Test for write permission.  */
-//#define   X_OK    1       /* execute permission - unsupported in windows*/
+#define X_OK    0       /* jkt: unsupported on Windows, so we don't really care */
 #define F_OK    0       /* Test for existence.  */
 
 #define access _access