diff --git a/legacy/src/llm.ts b/legacy/src/llm.ts
index 248ddf11..3510e90b 100644
--- a/legacy/src/llm.ts
+++ b/legacy/src/llm.ts
@@ -176,7 +176,7 @@ export abstract class BaseChatModelBuilder<
           omitTrailingSemicolon: true,
           noEmitHelpers: true
         })
-          .replace(/^    /gm, '  ')
+          .replace(/^ {4}/gm, '  ')
           .replace(/;$/gm, '')
 
         messages.push({