diff --git a/.changeset/eight-pots-invent.md b/.changeset/eight-pots-invent.md
index 285c5ff97..e46412a86 100644
--- a/.changeset/eight-pots-invent.md
+++ b/.changeset/eight-pots-invent.md
@@ -2,4 +2,4 @@
 "@ckb-lumos/lumos": minor
 ---
 
-BREAKING CHANGE: refine the export structure
+**BREAKING CHANGE**: refine the export structure
diff --git a/.changeset/purple-countries-fetch.md b/.changeset/purple-countries-fetch.md
new file mode 100644
index 000000000..526c813ef
--- /dev/null
+++ b/.changeset/purple-countries-fetch.md
@@ -0,0 +1,5 @@
+---
+"@ckb-lumos/ckb-indexer": minor
+---
+
+**BREAKING CHANGE**: correct the semantic of the `waitForSync`
diff --git a/packages/ckb-indexer/src/indexer.ts b/packages/ckb-indexer/src/indexer.ts
index 35663c6ec..db25a8db3 100644
--- a/packages/ckb-indexer/src/indexer.ts
+++ b/packages/ckb-indexer/src/indexer.ts
@@ -84,14 +84,14 @@ export class CkbIndexer implements CellProvider, TerminableCellFetcher {
     return new Promise((resolve) => setTimeout(resolve, timeout));
   }
 
-  async waitForSync(blockDifference = 0): Promise<void> {
+  async waitForSync(nextNBlocks = 0): Promise<void> {
     const rpcTipNumber = parseInt(
       (await this.getCkbRpc().getTipHeader()).number,
       16
     );
     while (true) {
       const indexerTipNumber = parseInt((await this.tip()).blockNumber, 16);
-      if (indexerTipNumber + blockDifference >= rpcTipNumber) {
+      if (indexerTipNumber - nextNBlocks >= rpcTipNumber) {
         return;
       }
       await this.asyncSleep(1000);