diff --git a/src/monitors/assets-transferred-monitor.ts b/src/monitors/assets-transferred-monitor.ts
index 0742beb..a55aca5 100644
--- a/src/monitors/assets-transferred-monitor.ts
+++ b/src/monitors/assets-transferred-monitor.ts
@@ -29,7 +29,7 @@ export class AssetsTransferredMonitor extends NineChroniclesMonitor<AssetTransfe
             await this._headlessGraphQLClient.getBlockHash(blockIndex);
         const events =
             await this._headlessGraphQLClient.getAssetTransferredEvents(
-                blockIndex,
+                blockIndex - 1,  // need to wait 1 block far from tip due to 9c headless' bug.
                 this._address,
             );
 
diff --git a/src/monitors/garage-unload-monitor.ts b/src/monitors/garage-unload-monitor.ts
index 2ba4ec4..100fe68 100644
--- a/src/monitors/garage-unload-monitor.ts
+++ b/src/monitors/garage-unload-monitor.ts
@@ -31,7 +31,7 @@ export class GarageUnloadMonitor extends NineChroniclesMonitor<GarageUnloadEvent
         const blockHash =
             await this._headlessGraphQLClient.getBlockHash(blockIndex);
         const events = await this._headlessGraphQLClient.getGarageUnloadEvents(
-            blockIndex,
+            blockIndex - 1, // need to wait 1 block far from tip due to 9c headless' bug.
             this._agentAddress,
             this._avatarAddress,
         );