1 files changed, 1 insertions, 1 deletions
diff --git a/src/libstd/io/error.rs b/src/libstd/io/error.rs
index 1dd96f5ddfc..e3f17c839f1 100644
--- a/src/libstd/io/error.rs
+++ b/src/libstd/io/error.rs
@@ -377,7 +377,7 @@ mod test {
         struct TestError;
 
         impl fmt::Display for TestError {
-            fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+            fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
                 Ok(())
             }
         }