diff --git a/src/lib.rs b/src/lib.rs
index 667230a..57959c0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,7 +1,7 @@
 #![allow(clippy::result_unit_err)]
 
 use std::{
-    os::mikros::{ipc::rpc::{self, IncomingCall}, Errno},
+    os::mikros::{ipc::rpc::{self, IncomingCall}, Errno, FileOpenMode},
     path::Path,
 };
 
@@ -13,7 +13,7 @@ const PROTO: u16 = 3;
 
 pub trait Server: Send + Sync {
     fn mount(&self, dev: &Path) -> Result<u64, Errno>;
-    fn open(&self, path: &Path, mount_id: u64) -> Result<(Option<u64>, u64), Errno>;
+    fn open(&self, path: &Path, mode: FileOpenMode, mount_id: u64) -> Result<(Option<u64>, u64), Errno>;
     fn open_dir(&self, path: &Path, mount_id: u64) -> Result<(Option<u64>, u64), Errno>;
 }
 
@@ -33,13 +33,13 @@ impl Client {
         .unwrap()
     }
 
-    pub fn open(self, path: &Path, mount_id: u64) -> Result<(Option<u64>, u64), Errno> {
+    pub fn open(self, path: &Path, mode: FileOpenMode, mount_id: u64) -> Result<(Option<u64>, u64), Errno> {
         postcard::from_bytes(
             &rpc::send_call(
                 self.0,
                 PROTO,
                 1,
-                &postcard::to_stdvec(&(path, mount_id)).unwrap(),
+                &postcard::to_stdvec(&(path, mode, mount_id)).unwrap(),
             )
             .get_return(),
         )
@@ -78,8 +78,8 @@ fn callback(call: IncomingCall) {
         let ret = postcard::to_stdvec(&server.mount(dev)).unwrap();
         call.send_return(&ret);
     } else if call.func == 1 {
-        let (path, mount_id) = postcard::from_bytes(call.args()).unwrap();
-        let ret = postcard::to_stdvec(&server.open(path, mount_id)).unwrap();
+        let (path, mode, mount_id) = postcard::from_bytes(call.args()).unwrap();
+        let ret = postcard::to_stdvec(&server.open(path, mode, mount_id)).unwrap();
         call.send_return(&ret);
     } else if call.func == 2 {
         let (path, mount_id) = postcard::from_bytes(call.args()).unwrap();