diff --git a/java/api/src/main/java/io/ray/api/id/JobId.java b/java/api/src/main/java/io/ray/api/id/JobId.java
index eba593fe4..48aa61e77 100644
--- a/java/api/src/main/java/io/ray/api/id/JobId.java
+++ b/java/api/src/main/java/io/ray/api/id/JobId.java
@@ -10,7 +10,7 @@ import java.util.Arrays;
  */
 public class JobId extends BaseId implements Serializable {
 
-  public static final int LENGTH = 2;
+  public static final int LENGTH = 4;
 
   public static final JobId NIL = genNil();
 
diff --git a/src/ray/core_worker/lib/java/jni_utils.h b/src/ray/core_worker/lib/java/jni_utils.h
index f7bb7e2d3..972b43f71 100644
--- a/src/ray/core_worker/lib/java/jni_utils.h
+++ b/src/ray/core_worker/lib/java/jni_utils.h
@@ -256,6 +256,8 @@ inline ID JavaByteArrayToId(JNIEnv *env, const jbyteArray &bytes) {
   std::string id_str(ID::Size(), 0);
   env->GetByteArrayRegion(bytes, 0, ID::Size(),
                           reinterpret_cast<jbyte *>(&id_str.front()));
+  auto arr_size = env->GetArrayLength(bytes)
+  RAY_CHECK(arr_size == ID::Size()) << "ID length should be " ID::Size() << " instead of " << arr_size;
   return ID::FromBinary(id_str);
 }