diff --git a/compiler/rustc_expand/src/mbe/macro_rules.rs b/compiler/rustc_expand/src/mbe/macro_rules.rs
index 37b236a2e268c..08b0efb74a05f 100644
--- a/compiler/rustc_expand/src/mbe/macro_rules.rs
+++ b/compiler/rustc_expand/src/mbe/macro_rules.rs
@@ -347,7 +347,7 @@ fn expand_macro_attr(
 
     if cx.trace_macros() {
         let msg = format!(
-            "expanding `$[{name}({})] {}`",
+            "expanding `#[{name}({})] {}`",
             pprust::tts_to_string(&args),
             pprust::tts_to_string(&body),
         );