diff --git a/services/powermanager/WorkSource.cpp b/services/powermanager/WorkSource.cpp
index 1006a06..64a5499 100644
--- a/services/powermanager/WorkSource.cpp
+++ b/services/powermanager/WorkSource.cpp
@@ -28,9 +28,16 @@
         return BAD_VALUE;
     }
     int32_t num;
+    int32_t workChainCount;
     status_t ret = parcel->readInt32(&num)
                 ?: parcel->readInt32Vector(&mUids)
-                ?: parcel->readString16Vector(&mNames);
+                ?: parcel->readString16Vector(&mNames)
+                ?: parcel->readInt32(&workChainCount);
+
+    if (ret == OK && workChainCount > 0) {
+        // We don't yet support WorkChains in native WorkSources.
+        return BAD_VALUE;
+    }
 
     return ret;
 }
@@ -43,7 +50,8 @@
 
     return parcel->writeInt32(mUids.size())
         ?: parcel->writeInt32Vector(mUids)
-        ?: parcel->writeString16Vector(mNames);
+        ?: parcel->writeString16Vector(mNames)
+        ?: parcel->writeInt32(-1);
 }
 
 } // namespace android::os
diff --git a/services/powermanager/tests/Android.bp b/services/powermanager/tests/Android.bp
index 2d1558a..962784c 100644
--- a/services/powermanager/tests/Android.bp
+++ b/services/powermanager/tests/Android.bp
@@ -31,6 +31,7 @@
         "PowerHalWrapperAidlTest.cpp",
         "PowerHalWrapperHidlV1_0Test.cpp",
         "PowerHalWrapperHidlV1_1Test.cpp",
+        "WorkSourceTest.cpp",
     ],
     cflags: [
         "-Wall",
diff --git a/services/powermanager/tests/WorkSourceTest.cpp b/services/powermanager/tests/WorkSourceTest.cpp
new file mode 100644
index 0000000..bb9164a
--- /dev/null
+++ b/services/powermanager/tests/WorkSourceTest.cpp
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <optional>
+#define LOG_TAG "PowerHalLoaderTest"
+
+#include <android-base/logging.h>
+#include <android/WorkSource.h>
+#include <binder/Parcel.h>
+#include <gtest/gtest.h>
+
+#include <future>
+
+using namespace android;
+using namespace testing;
+
+TEST(WorkSourceTest, Parcel) {
+    std::vector<int32_t> uids = {1, 2};
+    using Names = std::vector<std::optional<String16>>;
+    std::optional<Names> names = std::make_optional<Names>({std::make_optional(String16("name"))});
+    os::WorkSource ws{uids, names};
+
+    Parcel p;
+    ws.writeToParcel(&p);
+    p.setDataPosition(0);
+
+    os::WorkSource otherWs;
+    otherWs.readFromParcel(&p);
+
+    EXPECT_EQ(ws, otherWs);
+    EXPECT_EQ(uids, otherWs.getUids());
+    EXPECT_EQ(names, otherWs.getNames());
+}