diff --git a/src/lib/inbox/inbox.ts b/src/lib/inbox/inbox.ts
index 7e6f6a425..dc3c666d1 100644
--- a/src/lib/inbox/inbox.ts
+++ b/src/lib/inbox/inbox.ts
@@ -215,7 +215,7 @@ export class InboxTools {
           sequencerInbox.interface.decodeFunctionResult(
             'maxTimeVariation',
             returnData
-          )[0],
+          ) as Awaited<ReturnType<SequencerInbox['maxTimeVariation']>>,
       },
       multicall.getBlockNumberInput(),
       multicall.getCurrentBlockTimestampInput(),