diff --git a/artiq/runtime.rs/liblwip/lib.rs b/artiq/runtime.rs/liblwip/lib.rs
index dca02c857..49af078a0 100644
--- a/artiq/runtime.rs/liblwip/lib.rs
+++ b/artiq/runtime.rs/liblwip/lib.rs
@@ -375,7 +375,7 @@ impl TcpListener {
                 backlog: LinkedList::new()
             }));
             let arg = &mut *state as *mut RefCell<TcpListenerState> as *mut _;
-            lwip_sys::tcp_arg(raw, arg);
+            lwip_sys::tcp_arg(raw2, arg);
             lwip_sys::tcp_accept(raw2, accept);
             Ok(TcpListener { raw: raw2, state: state })
         }
diff --git a/artiq/runtime.rs/src/io.rs b/artiq/runtime.rs/src/io.rs
index fc7e802ae..0607be728 100644
--- a/artiq/runtime.rs/src/io.rs
+++ b/artiq/runtime.rs/src/io.rs
@@ -257,7 +257,6 @@ impl<'a> TcpListener<'a> {
 
     pub fn accept(&self) -> Result<(TcpStream, SocketAddr)> {
         try!(self.waiter.tcp_acceptable(&self.lower));
-        loop {}
         let stream_lower = self.lower.try_accept().unwrap();
         let addr = SocketAddr::new(IP_ANY, 0); // FIXME: coax lwip into giving real addr here
         Ok((TcpStream {