diff --git a/fluss-flink/fluss-flink-common/src/main/java/org/apache/fluss/flink/source/enumerator/FlinkSourceEnumerator.java b/fluss-flink/fluss-flink-common/src/main/java/org/apache/fluss/flink/source/enumerator/FlinkSourceEnumerator.java
index b537a81224..3ad234aa01 100644
--- a/fluss-flink/fluss-flink-common/src/main/java/org/apache/fluss/flink/source/enumerator/FlinkSourceEnumerator.java
+++ b/fluss-flink/fluss-flink-common/src/main/java/org/apache/fluss/flink/source/enumerator/FlinkSourceEnumerator.java
@@ -354,6 +354,10 @@ public void start() {
 
     private void startInBatchMode() {
         if (lakeEnabled) {
+            if (lakeSource == null) {
+                throw new IllegalStateException(
+                        "The 'lakeSource' is null in batch mode. It should be set if lake is enabled.");
+            }
             context.callAsync(
                     () -> {
                         List<SourceSplitBase> splits = generateHybridLakeFlussSplits();