diff --git a/src/simulateScript/deno-sandbox/sandbox.ts b/src/simulateScript/deno-sandbox/sandbox.ts
index b42c196..3dd002b 100644
--- a/src/simulateScript/deno-sandbox/sandbox.ts
+++ b/src/simulateScript/deno-sandbox/sandbox.ts
@@ -403,7 +403,7 @@ const Functions = {
     }
     if (typeof num === 'number') {
       if (!Number.isInteger(num)) {
-        throw new Error('input into Functions.encodeUint256 is not an integer')
+        throw new Error('input into Functions.encodeInt256 is not an integer')
       }
     }
     num = BigInt(num)