diff --git a/src/lib.rs b/src/lib.rs
index 10b0e9b..9fa2a29 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,
 };
 
@@ -12,7 +12,7 @@ static SERVER: RwLock<Option<Box<dyn Server>>> = RwLock::new(None);
 const PROTO: u16 = 0;
 
 pub trait Server: Send + Sync {
-    fn open(&self, path: &Path) -> Result<u64, Errno>;
+    fn open(&self, path: &Path, mode: FileOpenMode) -> Result<u64, Errno>;
 }
 
 #[derive(Copy, Clone)]
@@ -23,9 +23,9 @@ impl Client {
         Self(pid)
     }
 
-    pub fn open(self, path: &Path) -> Result<u64, Errno> {
+    pub fn open(self, path: &Path, mode: FileOpenMode) -> Result<u64, Errno> {
         postcard::from_bytes(
-            &rpc::send_call(self.0, PROTO, 0, &postcard::to_stdvec(path).unwrap()).get_return(),
+            &rpc::send_call(self.0, PROTO, 0, &postcard::to_stdvec(&(path, mode)).unwrap()).get_return(),
         )
         .unwrap()
     }
@@ -45,8 +45,8 @@ fn callback(call: IncomingCall) {
     let server_lock = SERVER.read();
     let server = server_lock.as_ref().unwrap();
     if call.func == 0 {
-        let path = postcard::from_bytes(call.args()).unwrap();
-        let ret = postcard::to_stdvec(&server.open(path)).unwrap();
+        let (path, mode) = postcard::from_bytes(call.args()).unwrap();
+        let ret = postcard::to_stdvec(&server.open(path, mode)).unwrap();
         call.send_return(&ret);
     }
 }