diff --git a/cli/generate/src/prepare_grammar/flatten_grammar.rs b/cli/generate/src/prepare_grammar/flatten_grammar.rs
index b8033d5f..bffd3ef9 100644
--- a/cli/generate/src/prepare_grammar/flatten_grammar.rs
+++ b/cli/generate/src/prepare_grammar/flatten_grammar.rs
@@ -533,7 +533,7 @@ mod tests {
 
         assert_eq!(
             result.unwrap_err().to_string(),
-            "Rule `test` cannot be inlined because it contains a reference to itself.",
+            "Rule `test` cannot be inlined because it contains a reference to itself",
         );
     }
 }