diff --git a/src/compiletest/procsrv.rs b/src/compiletest/procsrv.rs
index 892ed15fb33..e82ef76b3a3 100644
--- a/src/compiletest/procsrv.rs
+++ b/src/compiletest/procsrv.rs
@@ -26,7 +26,7 @@ fn target_env(lib_path: str, prog: str) -> option<[(str,str)]> {
 #[cfg(target_os = "linux")]
 #[cfg(target_os = "macos")]
 #[cfg(target_os = "freebsd")]
-fn target_env(lib_path: str, prog: str) -> option<[(str,str)]> {
+fn target_env(_lib_path: str, _prog: str) -> option<[(str,str)]> {
     none
 }