diff --git a/src/Eio/OpenFlagResolver.php b/src/Eio/OpenFlagResolver.php
index e6b7637f..d09b1da3 100644
--- a/src/Eio/OpenFlagResolver.php
+++ b/src/Eio/OpenFlagResolver.php
@@ -14,7 +14,6 @@ class OpenFlagResolver extends FlagResolver implements FlagResolverInterface
         'a' => EIO_O_APPEND,
         'c' => EIO_O_CREAT,
         'e' => EIO_O_EXCL,
-        'f' => EIO_O_FSYNC,
         'n' => EIO_O_NONBLOCK,
         'r' => EIO_O_RDONLY,
         't' => EIO_O_TRUNC,