diff --git a/services/surfaceflinger/EventThread.cpp b/services/surfaceflinger/EventThread.cpp
index bc271c8..5a8fd25 100644
--- a/services/surfaceflinger/EventThread.cpp
+++ b/services/surfaceflinger/EventThread.cpp
@@ -155,20 +155,17 @@
     mCondition.notify_all();
 }
 
-void EventThread::onHotplugReceived(int type, bool connected) {
-    ALOGE_IF(type >= DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES,
-             "received hotplug event for an invalid display (id=%d)", type);
-
+void EventThread::onHotplugReceived(DisplayType displayType, bool connected) {
     std::lock_guard<std::mutex> lock(mMutex);
-    if (type < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES) {
-        DisplayEventReceiver::Event event;
-        event.header.type = DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG;
-        event.header.id = type;
-        event.header.timestamp = systemTime();
-        event.hotplug.connected = connected;
-        mPendingEvents.add(event);
-        mCondition.notify_all();
-    }
+
+    DisplayEventReceiver::Event event;
+    event.header.type = DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG;
+    event.header.id = displayType == DisplayType::Primary ? 0 : 1;
+    event.header.timestamp = systemTime();
+    event.hotplug.connected = connected;
+
+    mPendingEvents.add(event);
+    mCondition.notify_all();
 }
 
 void EventThread::threadMain() NO_THREAD_SAFETY_ANALYSIS {
@@ -205,7 +202,7 @@
 // This will return when (1) a vsync event has been received, and (2) there was
 // at least one connection interested in receiving it when we started waiting.
 Vector<sp<EventThread::Connection> > EventThread::waitForEventLocked(
-        std::unique_lock<std::mutex>* lock, DisplayEventReceiver::Event* event) {
+        std::unique_lock<std::mutex>* lock, DisplayEventReceiver::Event* outEvent) {
     Vector<sp<EventThread::Connection> > signalConnections;
 
     while (signalConnections.isEmpty() && mKeepRunning) {
@@ -214,16 +211,16 @@
 
         size_t vsyncCount = 0;
         nsecs_t timestamp = 0;
-        for (int32_t i = 0; i < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES; i++) {
-            timestamp = mVSyncEvent[i].header.timestamp;
+        for (auto& event : mVSyncEvent) {
+            timestamp = event.header.timestamp;
             if (timestamp) {
                 // we have a vsync event to dispatch
                 if (mInterceptVSyncsCallback) {
                     mInterceptVSyncsCallback(timestamp);
                 }
-                *event = mVSyncEvent[i];
-                mVSyncEvent[i].header.timestamp = 0;
-                vsyncCount = mVSyncEvent[i].vsync.count;
+                *outEvent = event;
+                event.header.timestamp = 0;
+                vsyncCount = event.vsync.count;
                 break;
             }
         }
@@ -233,7 +230,7 @@
             eventPending = !mPendingEvents.isEmpty();
             if (eventPending) {
                 // we have some other event to dispatch
-                *event = mPendingEvents[0];
+                *outEvent = mPendingEvents[0];
                 mPendingEvents.removeAt(0);
             }
         }
@@ -319,7 +316,7 @@
                     // FIXME: how do we decide which display id the fake
                     // vsync came from ?
                     mVSyncEvent[0].header.type = DisplayEventReceiver::DISPLAY_EVENT_VSYNC;
-                    mVSyncEvent[0].header.id = DisplayDevice::DISPLAY_PRIMARY;
+                    mVSyncEvent[0].header.id = 0;
                     mVSyncEvent[0].header.timestamp = systemTime(SYSTEM_TIME_MONOTONIC);
                     mVSyncEvent[0].vsync.count++;
                 }
@@ -364,8 +361,7 @@
     result.appendFormat("VSYNC state: %s\n", mDebugVsyncEnabled ? "enabled" : "disabled");
     result.appendFormat("  soft-vsync: %s\n", mUseSoftwareVSync ? "enabled" : "disabled");
     result.appendFormat("  numListeners=%zu,\n  events-delivered: %u\n",
-                        mDisplayEventConnections.size(),
-                        mVSyncEvent[DisplayDevice::DISPLAY_PRIMARY].vsync.count);
+                        mDisplayEventConnections.size(), mVSyncEvent[0].vsync.count);
     for (size_t i = 0; i < mDisplayEventConnections.size(); i++) {
         sp<Connection> connection = mDisplayEventConnections.itemAt(i).promote();
         result.appendFormat("    %p: count=%d\n", connection.get(),
diff --git a/services/surfaceflinger/EventThread.h b/services/surfaceflinger/EventThread.h
index 9c13ed2..a0262b2 100644
--- a/services/surfaceflinger/EventThread.h
+++ b/services/surfaceflinger/EventThread.h
@@ -16,9 +16,11 @@
 
 #pragma once
 
-#include <stdint.h>
 #include <sys/types.h>
+
+#include <array>
 #include <condition_variable>
+#include <cstdint>
 #include <mutex>
 #include <thread>
 
@@ -31,8 +33,6 @@
 #include <utils/Errors.h>
 #include <utils/SortedVector.h>
 
-#include "DisplayDevice.h"
-
 // ---------------------------------------------------------------------------
 namespace android {
 // ---------------------------------------------------------------------------
@@ -59,6 +59,9 @@
 
 class EventThread {
 public:
+    // TODO: Remove once stable display IDs are plumbed through SF/WM interface.
+    enum class DisplayType { Primary, External };
+
     virtual ~EventThread();
 
     virtual sp<BnDisplayEventConnection> createEventConnection() const = 0;
@@ -70,7 +73,7 @@
     virtual void onScreenAcquired() = 0;
 
     // called when receiving a hotplug event
-    virtual void onHotplugReceived(int type, bool connected) = 0;
+    virtual void onHotplugReceived(DisplayType displayType, bool connected) = 0;
 
     virtual void dump(String8& result) const = 0;
 
@@ -122,7 +125,7 @@
     void onScreenAcquired() override;
 
     // called when receiving a hotplug event
-    void onHotplugReceived(int type, bool connected) override;
+    void onHotplugReceived(DisplayType displayType, bool connected) override;
 
     void dump(String8& result) const override;
 
@@ -155,8 +158,7 @@
     // protected by mLock
     SortedVector<wp<Connection>> mDisplayEventConnections GUARDED_BY(mMutex);
     Vector<DisplayEventReceiver::Event> mPendingEvents GUARDED_BY(mMutex);
-    DisplayEventReceiver::Event mVSyncEvent[DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES] GUARDED_BY(
-            mMutex);
+    std::array<DisplayEventReceiver::Event, 2> mVSyncEvent GUARDED_BY(mMutex);
     bool mUseSoftwareVSync GUARDED_BY(mMutex) = false;
     bool mVsyncEnabled GUARDED_BY(mMutex) = false;
     bool mKeepRunning GUARDED_BY(mMutex) = true;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index db534cc..5acf2b8 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2293,8 +2293,11 @@
                 if (const auto display = getDisplayDeviceLocked(draw.keyAt(i))) {
                     display->disconnect(getHwComposer());
                 }
-                if (draw[i].type < DisplayDevice::NUM_BUILTIN_DISPLAY_TYPES)
-                    mEventThread->onHotplugReceived(draw[i].type, false);
+                if (draw[i].type == DisplayDevice::DISPLAY_PRIMARY) {
+                    mEventThread->onHotplugReceived(EventThread::DisplayType::Primary, false);
+                } else if (draw[i].type == DisplayDevice::DISPLAY_EXTERNAL) {
+                    mEventThread->onHotplugReceived(EventThread::DisplayType::External, false);
+                }
                 mDisplays.erase(draw.keyAt(i));
             } else {
                 // this display is in both lists. see if something changed.
@@ -2395,7 +2398,13 @@
                                       setupNewDisplayDeviceInternal(displayToken, displayId, state,
                                                                     dispSurface, producer));
                     if (!state.isVirtual()) {
-                        mEventThread->onHotplugReceived(state.type, true);
+                        if (state.type == DisplayDevice::DISPLAY_PRIMARY) {
+                            mEventThread->onHotplugReceived(EventThread::DisplayType::Primary,
+                                                            true);
+                        } else if (state.type == DisplayDevice::DISPLAY_EXTERNAL) {
+                            mEventThread->onHotplugReceived(EventThread::DisplayType::External,
+                                                            true);
+                        }
                     }
                 }
             }
diff --git a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
index 7928cba..8d18d76 100644
--- a/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/DisplayTransactionTest.cpp
@@ -1165,13 +1165,23 @@
     Case::PerFrameMetadataSupport::setupComposerCallExpectations(this);
 
     EXPECT_CALL(*mSurfaceInterceptor, saveDisplayCreation(_)).Times(1);
-    EXPECT_CALL(*mEventThread, onHotplugReceived(Case::Display::TYPE, true)).Times(1);
+    EXPECT_CALL(*mEventThread,
+                onHotplugReceived(Case::Display::TYPE == DisplayDevice::DISPLAY_PRIMARY
+                                          ? EventThread::DisplayType::Primary
+                                          : EventThread::DisplayType::External,
+                                  true))
+            .Times(1);
 }
 
 template <typename Case>
 void HandleTransactionLockedTest::setupCommonCallExpectationsForDisconnectProcessing() {
     EXPECT_CALL(*mSurfaceInterceptor, saveDisplayDeletion(_)).Times(1);
-    EXPECT_CALL(*mEventThread, onHotplugReceived(Case::Display::TYPE, false)).Times(1);
+    EXPECT_CALL(*mEventThread,
+                onHotplugReceived(Case::Display::TYPE == DisplayDevice::DISPLAY_PRIMARY
+                                          ? EventThread::DisplayType::Primary
+                                          : EventThread::DisplayType::External,
+                                  false))
+            .Times(1);
 }
 
 template <typename Case>
diff --git a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
index 80fdb80..19747bd 100644
--- a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
+++ b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
@@ -71,7 +71,8 @@
                                               ConnectionEventRecorder& connectionEventRecorder,
                                               nsecs_t expectedTimestamp, unsigned expectedCount);
     void expectVsyncEventReceivedByConnection(nsecs_t expectedTimestamp, unsigned expectedCount);
-    void expectHotplugEventReceivedByConnection(int expectedDisplayType, bool expectedConnected);
+    void expectHotplugEventReceivedByConnection(EventThread::DisplayType expectedDisplayType,
+                                                bool expectedConnected);
 
     AsyncCallRecorder<void (*)(bool)> mVSyncSetEnabledCallRecorder;
     AsyncCallRecorder<void (*)(VSyncSource::Callback*)> mVSyncSetCallbackCallRecorder;
@@ -169,13 +170,16 @@
                                          expectedCount);
 }
 
-void EventThreadTest::expectHotplugEventReceivedByConnection(int expectedDisplayType,
-                                                             bool expectedConnected) {
+void EventThreadTest::expectHotplugEventReceivedByConnection(
+        EventThread::DisplayType expectedDisplayType, bool expectedConnected) {
+    const uint32_t expectedDisplayId =
+            expectedDisplayType == EventThread::DisplayType::Primary ? 0 : 1;
+
     auto args = mConnectionEventCallRecorder.waitForCall();
     ASSERT_TRUE(args.has_value());
     const auto& event = std::get<0>(args.value());
     EXPECT_EQ(DisplayEventReceiver::DISPLAY_EVENT_HOTPLUG, event.header.type);
-    EXPECT_EQ(static_cast<unsigned>(expectedDisplayType), event.header.id);
+    EXPECT_EQ(expectedDisplayId, event.header.id);
     EXPECT_EQ(expectedConnected, event.hotplug.connected);
 }
 
@@ -394,28 +398,23 @@
 }
 
 TEST_F(EventThreadTest, postHotplugPrimaryDisconnect) {
-    mThread->onHotplugReceived(DisplayDevice::DISPLAY_PRIMARY, false);
-    expectHotplugEventReceivedByConnection(DisplayDevice::DISPLAY_PRIMARY, false);
+    mThread->onHotplugReceived(EventThread::DisplayType::Primary, false);
+    expectHotplugEventReceivedByConnection(EventThread::DisplayType::Primary, false);
 }
 
 TEST_F(EventThreadTest, postHotplugPrimaryConnect) {
-    mThread->onHotplugReceived(DisplayDevice::DISPLAY_PRIMARY, true);
-    expectHotplugEventReceivedByConnection(DisplayDevice::DISPLAY_PRIMARY, true);
+    mThread->onHotplugReceived(EventThread::DisplayType::Primary, true);
+    expectHotplugEventReceivedByConnection(EventThread::DisplayType::Primary, true);
 }
 
 TEST_F(EventThreadTest, postHotplugExternalDisconnect) {
-    mThread->onHotplugReceived(DisplayDevice::DISPLAY_EXTERNAL, false);
-    expectHotplugEventReceivedByConnection(DisplayDevice::DISPLAY_EXTERNAL, false);
+    mThread->onHotplugReceived(EventThread::DisplayType::External, false);
+    expectHotplugEventReceivedByConnection(EventThread::DisplayType::External, false);
 }
 
 TEST_F(EventThreadTest, postHotplugExternalConnect) {
-    mThread->onHotplugReceived(DisplayDevice::DISPLAY_EXTERNAL, true);
-    expectHotplugEventReceivedByConnection(DisplayDevice::DISPLAY_EXTERNAL, true);
-}
-
-TEST_F(EventThreadTest, postHotplugVirtualDisconnectIsFilteredOut) {
-    mThread->onHotplugReceived(DisplayDevice::DISPLAY_VIRTUAL, false);
-    EXPECT_FALSE(mConnectionEventCallRecorder.waitForUnexpectedCall().has_value());
+    mThread->onHotplugReceived(EventThread::DisplayType::External, true);
+    expectHotplugEventReceivedByConnection(EventThread::DisplayType::External, true);
 }
 
 } // namespace
diff --git a/services/surfaceflinger/tests/unittests/mock/MockEventThread.h b/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
index e6ea663..df9bfc6 100644
--- a/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
+++ b/services/surfaceflinger/tests/unittests/mock/MockEventThread.h
@@ -31,7 +31,7 @@
     MOCK_CONST_METHOD0(createEventConnection, sp<BnDisplayEventConnection>());
     MOCK_METHOD0(onScreenReleased, void());
     MOCK_METHOD0(onScreenAcquired, void());
-    MOCK_METHOD2(onHotplugReceived, void(int, bool));
+    MOCK_METHOD2(onHotplugReceived, void(DisplayType, bool));
     MOCK_CONST_METHOD1(dump, void(String8&));
     MOCK_METHOD1(setPhaseOffset, void(nsecs_t phaseOffset));
 };