diff --git a/packages/taiko-client/pkg/chain_iterator/event_iterator/block_proposed_iterator.go b/packages/taiko-client/pkg/chain_iterator/event_iterator/block_proposed_iterator.go
index 67fc0fea23d..e33fc4a5af9 100644
--- a/packages/taiko-client/pkg/chain_iterator/event_iterator/block_proposed_iterator.go
+++ b/packages/taiko-client/pkg/chain_iterator/event_iterator/block_proposed_iterator.go
@@ -170,6 +170,14 @@ func assembleBlockProposedIteratorCallback(
 			updateCurrentFunc(current)
 		}
 
+		// Check iterator errors.
+		if iter.Error() != nil {
+			return iter.Error()
+		}
+		if iterOntake.Error() != nil {
+			return iter.Error()
+		}
+
 		return nil
 	}
 }