diff --git a/src/main/java/cn/lihongjie/coal/common/CollectionUtils.java b/src/main/java/cn/lihongjie/coal/common/CollectionUtils.java
index e1b1b339..fa00b9b0 100644
--- a/src/main/java/cn/lihongjie/coal/common/CollectionUtils.java
+++ b/src/main/java/cn/lihongjie/coal/common/CollectionUtils.java
@@ -5,6 +5,7 @@ import lombok.experimental.UtilityClass;
 import org.apache.commons.lang3.ObjectUtils;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.function.BiFunction;
@@ -47,7 +48,7 @@ public class CollectionUtils {
     public static <A, B, K> List<Tuple2<A, B>> leftHashJoin(Iterable<A> a, Iterable<B> b, Function<A, K> ak, Function<B, K> bk) {
         Map<K, List<A>> aMap = newStream(a).collect(Collectors.groupingBy(ak));
         Map<K, List<B>> bMap = newStream(b).collect(Collectors.groupingBy(bk));
-        return aMap.keySet().stream().flatMap(k -> aMap.getOrDefault(k, new ArrayList<>()).stream().flatMap(av -> bMap.getOrDefault(k, List.of((B) null)).stream().map(bv -> new Tuple2<>(av, bv)))).collect(java.util.stream.Collectors.toList());
+        return aMap.keySet().stream().flatMap(k -> aMap.getOrDefault(k, new ArrayList<>()).stream().flatMap(av -> bMap.getOrDefault(k, new ArrayList<>(Arrays.asList((B)null))).stream().map(bv -> new Tuple2<>(av, bv)))).collect(java.util.stream.Collectors.toList());
     }
 
     public static <A, B> List<Tuple2<A, B>> leftNestJoin(Iterable<A> a, Iterable<B> b, BiFunction<A, B, Boolean> test) {