diff --git a/src/libnative/io/mod.rs b/src/libnative/io/mod.rs
index 90f8f6c214e..a541712e17f 100644
--- a/src/libnative/io/mod.rs
+++ b/src/libnative/io/mod.rs
@@ -301,8 +301,4 @@ fn tty_open(&mut self, fd: c_int, _readable: bool)
             })
         }
     }
-    fn signal(&mut self, _signal: int, _cb: Box<rtio::Callback>)
-              -> IoResult<Box<rtio::RtioSignal + Send>> {
-        Err(unimpl())
-    }
 }
diff --git a/src/librustrt/rtio.rs b/src/librustrt/rtio.rs
index a08bc697602..e9bee19b498 100644
--- a/src/librustrt/rtio.rs
+++ b/src/librustrt/rtio.rs
@@ -233,8 +233,6 @@ fn spawn(&mut self, cfg: ProcessConfig)
     fn pipe_open(&mut self, fd: c_int) -> IoResult<Box<RtioPipe + Send>>;
     fn tty_open(&mut self, fd: c_int, readable: bool)
             -> IoResult<Box<RtioTTY + Send>>;
-    fn signal(&mut self, signal: int, cb: Box<Callback + Send>)
-        -> IoResult<Box<RtioSignal + Send>>;
 }
 
 pub trait RtioTcpListener : RtioSocket {