1 files changed, 1 insertions, 1 deletions

diff --git a/crates/mbe/src/lib.rs b/crates/mbe/src/lib.rs
index 844e5a117..2d0763c47 100644
--- a/crates/mbe/src/lib.rs
+++ b/crates/mbe/src/lib.rs
@@ -52,7 +52,7 @@ impl fmt::Display for ExpandError {
             ExpandError::BindingError(e) => f.write_str(e),
             ExpandError::ConversionError => f.write_str("could not convert tokens"),
             ExpandError::InvalidRepeat => f.write_str("invalid repeat expression"),
-            ExpandError::ProcMacroError(e) => write!(f, "{}", e),
+            ExpandError::ProcMacroError(e) => e.fmt(f),
             ExpandError::Other(e) => f.write_str(e),
         }
     }