diff --git a/hardware_android_unittest.cc b/hardware_android_unittest.cc
new file mode 100644
index 0000000..9a491f3
--- /dev/null
+++ b/hardware_android_unittest.cc
@@ -0,0 +1,67 @@
+//
+// Copyright (C) 2020 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 <gtest/gtest.h>
+
+#include "update_engine/common/error_code.h"
+#include "update_engine/common/test_utils.h"
+#include "update_engine/hardware_android.h"
+
+namespace chromeos_update_engine {
+
+TEST(HardwareAndroidTest, IsKernelUpdateValid) {
+  EXPECT_EQ(ErrorCode::kSuccess,
+            HardwareAndroid::IsKernelUpdateValid("5.4.42-not-gki", ""))
+      << "Legacy update should be fine";
+
+  EXPECT_EQ(ErrorCode::kSuccess,
+            HardwareAndroid::IsKernelUpdateValid("5.4.42-not-gki",
+                                                 "5.4.42-android12-0"))
+      << "Update to GKI should be fine";
+
+  EXPECT_EQ(
+      ErrorCode::kDownloadManifestParseError,
+      HardwareAndroid::IsKernelUpdateValid("5.4.42-not-gki", "5.4.42-not-gki"))
+      << "Should report parse error for invalid version field";
+
+  EXPECT_EQ(ErrorCode::kSuccess,
+            HardwareAndroid::IsKernelUpdateValid(
+                "5.4.42-android12-0-something", "5.4.42-android12-0-something"))
+      << "Self update should be fine";
+
+  EXPECT_EQ(ErrorCode::kSuccess,
+            HardwareAndroid::IsKernelUpdateValid(
+                "5.4.42-android12-0-something", "5.4.43-android12-0-something"))
+      << "Sub-level update should be fine";
+
+  EXPECT_EQ(
+      ErrorCode::kSuccess,
+      HardwareAndroid::IsKernelUpdateValid("5.4.42-android12-0-something",
+                                           "5.10.10-android12-0-something"))
+      << "KMI version update should be fine";
+
+  EXPECT_EQ(ErrorCode::kPayloadTimestampError,
+            HardwareAndroid::IsKernelUpdateValid("5.4.42-android12-0-something",
+                                                 "5.4.5-android12-0-something"))
+      << "Should detect sub-level downgrade";
+
+  EXPECT_EQ(ErrorCode::kPayloadTimestampError,
+            HardwareAndroid::IsKernelUpdateValid("5.4.42-android12-0-something",
+                                                 "5.1.5-android12-0-something"))
+      << "Should detect KMI version downgrade";
+}
+
+}  // namespace chromeos_update_engine