diff --git a/tokio/src/sync/mutex.rs b/tokio/src/sync/mutex.rs
index 95b69e6281c..4d9f9886d76 100644
--- a/tokio/src/sync/mutex.rs
+++ b/tokio/src/sync/mutex.rs
@@ -496,14 +496,14 @@ where
     }
 }
 
-impl<T> std::fmt::Debug for Mutex<T>
+impl<T: ?Sized> std::fmt::Debug for Mutex<T>
 where
     T: std::fmt::Debug,
 {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let mut d = f.debug_struct("Mutex");
         match self.try_lock() {
-            Ok(inner) => d.field("data", &*inner),
+            Ok(inner) => d.field("data", &&*inner),
             Err(_) => d.field("data", &format_args!("<locked>")),
         };
         d.finish()