diff --git a/src/executor/executor.ts b/src/executor/executor.ts
index 13faf9b9..fb0634ea 100644
--- a/src/executor/executor.ts
+++ b/src/executor/executor.ts
@@ -730,7 +730,7 @@ export class Executor {
 
             if (
                 e?.details
-                    .toLowerCase()
+                    ?.toLowerCase()
                     .includes("replacement transaction underpriced")
             ) {
                 childLogger.error(