diff --git a/src/rstd/cast.rs b/src/rstd/cast.rs
index 3bc5dff..cbfd72b 100644
--- a/src/rstd/cast.rs
+++ b/src/rstd/cast.rs
@@ -52,7 +52,7 @@ impl<'a> Display for CastError<'a> {
                 index,
             } => write!(
                 f,
-                "address mismatch at index {}: {}>={}",
+                "address mismatch at index {}: {}!={}",
                 index,
                 hex::encode(expected),
                 hex::encode(received),