diff --git a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
index e499ff5..406ec81 100644
--- a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
+++ b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
@@ -81,6 +81,8 @@
     void expectVsyncEventReceivedByConnection(nsecs_t expectedTimestamp, unsigned expectedCount);
     void expectHotplugEventReceivedByConnection(PhysicalDisplayId expectedDisplayId,
                                                 bool expectedConnected);
+    void expectConfigChangedEventReceivedByConnection(PhysicalDisplayId expectedDisplayId,
+                                                      int32_t expectedConfigId);
 
     AsyncCallRecorder<void (*)(bool)> mVSyncSetEnabledCallRecorder;
     AsyncCallRecorder<void (*)(VSyncSource::Callback*)> mVSyncSetCallbackCallRecorder;
@@ -212,6 +214,16 @@
     EXPECT_EQ(expectedConnected, event.hotplug.connected);
 }
 
+void EventThreadTest::expectConfigChangedEventReceivedByConnection(
+        PhysicalDisplayId expectedDisplayId, int32_t expectedConfigId) {
+    auto args = mConnectionEventCallRecorder.waitForCall();
+    ASSERT_TRUE(args.has_value());
+    const auto& event = std::get<0>(args.value());
+    EXPECT_EQ(DisplayEventReceiver::DISPLAY_EVENT_CONFIG_CHANGED, event.header.type);
+    EXPECT_EQ(expectedDisplayId, event.header.displayId);
+    EXPECT_EQ(expectedConfigId, event.config.configId);
+}
+
 namespace {
 
 /* ------------------------------------------------------------------------
@@ -448,5 +460,15 @@
     expectHotplugEventReceivedByConnection(EXTERNAL_DISPLAY_ID, true);
 }
 
+TEST_F(EventThreadTest, postConfigChangedPrimary) {
+    mThread->onConfigChanged(INTERNAL_DISPLAY_ID, 7);
+    expectConfigChangedEventReceivedByConnection(INTERNAL_DISPLAY_ID, 7);
+}
+
+TEST_F(EventThreadTest, postConfigChangedExternal) {
+    mThread->onConfigChanged(EXTERNAL_DISPLAY_ID, 5);
+    expectConfigChangedEventReceivedByConnection(EXTERNAL_DISPLAY_ID, 5);
+}
+
 } // namespace
 } // namespace android
diff --git a/services/surfaceflinger/tests/unittests/mock/MockEventThread.h b/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
index 5edee6e..cb4a300 100644
--- a/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
+++ b/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
@@ -33,6 +33,7 @@
     MOCK_METHOD0(onScreenReleased, void());
     MOCK_METHOD0(onScreenAcquired, void());
     MOCK_METHOD2(onHotplugReceived, void(PhysicalDisplayId, bool));
+    MOCK_METHOD2(onConfigChanged, void(PhysicalDisplayId, int32_t));
     MOCK_CONST_METHOD1(dump, void(std::string&));
     MOCK_METHOD1(setPhaseOffset, void(nsecs_t phaseOffset));
     MOCK_METHOD1(registerDisplayEventConnection,