diff --git a/logservice/eventstore/event_store.go b/logservice/eventstore/event_store.go
index d85319b97c..0a171de62d 100644
--- a/logservice/eventstore/event_store.go
+++ b/logservice/eventstore/event_store.go
@@ -28,6 +28,7 @@ import (
 	"github.com/cockroachdb/pebble"
 	"github.com/klauspost/compress/zstd"
 	"github.com/pingcap/errors"
+	"github.com/pingcap/failpoint"
 	"github.com/pingcap/log"
 	"github.com/pingcap/ticdc/heartbeatpb"
 	"github.com/pingcap/ticdc/logservice/logpuller"
@@ -1521,6 +1522,9 @@ func (e *eventStore) writeEvents(
 	}
 	metrics.EventStoreWritePrepareDurationHistogram.Observe(time.Since(prepareStart).Seconds())
 	start := time.Now()
+	// Simulate slow EventStore storage so write workers remain occupied and
+	// incoming events queue up behind them.
+	failpoint.Inject("SlowEventStoreWrite", nil)
 	err := batch.Commit(pebble.NoSync)
 	metrics.EventStoreWriteDurationHistogram.Observe(time.Since(start).Seconds())
 	return err