diff --git a/src/librustc/middle/typeck/infer/coercion.rs b/src/librustc/middle/typeck/infer/coercion.rs
index fac84281f7fe..f0fe2deffdfa 100644
--- a/src/librustc/middle/typeck/infer/coercion.rs
+++ b/src/librustc/middle/typeck/infer/coercion.rs
@@ -196,7 +196,7 @@ impl Coerce {
         let inner_ty = match *sty_a {
             ty::ty_box(mt_a) => mt_a.ty,
             ty::ty_uniq(mt_a) => mt_a.ty,
-            ty::ty_rptr(r_a, mt_a) => mt_a.ty,
+            ty::ty_rptr(_, mt_a) => mt_a.ty,
             _ => {
                 return self.subtype(a, b);
             }