diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index fcc52a8..e26cee4 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -27,6 +27,7 @@
 #include <JoystickInputMapper.h>
 #include <KeyboardInputMapper.h>
 #include <MultiTouchInputMapper.h>
+#include <NotifyArgsBuilders.h>
 #include <PeripheralController.h>
 #include <SensorInputMapper.h>
 #include <SingleTouchInputMapper.h>
@@ -1184,6 +1185,82 @@
     mFakeListener->assertNotifyCaptureWasNotCalled();
 }
 
+TEST_F(InputReaderTest, GetLastUsedInputDeviceId) {
+    constexpr int32_t FIRST_DEVICE_ID = END_RESERVED_ID + 1000;
+    constexpr int32_t SECOND_DEVICE_ID = FIRST_DEVICE_ID + 1;
+    FakeInputMapper& firstMapper =
+            addDeviceWithFakeInputMapper(FIRST_DEVICE_ID, FIRST_DEVICE_ID, "first",
+                                         InputDeviceClass::KEYBOARD, AINPUT_SOURCE_KEYBOARD,
+                                         /*configuration=*/nullptr);
+    FakeInputMapper& secondMapper =
+            addDeviceWithFakeInputMapper(SECOND_DEVICE_ID, SECOND_DEVICE_ID, "second",
+                                         InputDeviceClass::TOUCH_MT, AINPUT_SOURCE_STYLUS,
+                                         /*configuration=*/nullptr);
+
+    ASSERT_EQ(ReservedInputDeviceId::INVALID_INPUT_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+
+    // Start a new key gesture from the first device
+    firstMapper.setProcessResult({KeyArgsBuilder(AKEY_EVENT_ACTION_DOWN, AINPUT_SOURCE_KEYBOARD)
+                                          .deviceId(FIRST_DEVICE_ID)
+                                          .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, FIRST_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(firstMapper.getDeviceId(), mReader->getLastUsedInputDeviceId());
+
+    // Start a new touch gesture from the second device
+    secondMapper.setProcessResult(
+            {MotionArgsBuilder(AMOTION_EVENT_ACTION_DOWN, AINPUT_SOURCE_STYLUS)
+                     .deviceId(SECOND_DEVICE_ID)
+                     .pointer(PointerBuilder(/*id=*/0, ToolType::FINGER))
+                     .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, SECOND_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(SECOND_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+
+    // Releasing the key is not a new gesture, so it does not update the last used device
+    firstMapper.setProcessResult({KeyArgsBuilder(AKEY_EVENT_ACTION_UP, AINPUT_SOURCE_KEYBOARD)
+                                          .deviceId(FIRST_DEVICE_ID)
+                                          .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, FIRST_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(SECOND_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+
+    // But pressing a new key does start a new gesture
+    firstMapper.setProcessResult({KeyArgsBuilder(AKEY_EVENT_ACTION_DOWN, AINPUT_SOURCE_KEYBOARD)
+                                          .deviceId(FIRST_DEVICE_ID)
+                                          .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, FIRST_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(FIRST_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+
+    // Moving or ending a touch gesture does not update the last used device
+    secondMapper.setProcessResult(
+            {MotionArgsBuilder(AMOTION_EVENT_ACTION_MOVE, AINPUT_SOURCE_STYLUS)
+                     .deviceId(SECOND_DEVICE_ID)
+                     .pointer(PointerBuilder(/*id=*/0, ToolType::STYLUS))
+                     .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, SECOND_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(FIRST_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+    secondMapper.setProcessResult({MotionArgsBuilder(AMOTION_EVENT_ACTION_UP, AINPUT_SOURCE_STYLUS)
+                                           .deviceId(SECOND_DEVICE_ID)
+                                           .pointer(PointerBuilder(/*id=*/0, ToolType::STYLUS))
+                                           .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, SECOND_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(FIRST_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+
+    // Starting a new hover gesture updates the last used device
+    secondMapper.setProcessResult(
+            {MotionArgsBuilder(AMOTION_EVENT_ACTION_HOVER_ENTER, AINPUT_SOURCE_STYLUS)
+                     .deviceId(SECOND_DEVICE_ID)
+                     .pointer(PointerBuilder(/*id=*/0, ToolType::STYLUS))
+                     .build()});
+    mFakeEventHub->enqueueEvent(ARBITRARY_TIME, ARBITRARY_TIME, SECOND_DEVICE_ID, 0, 0, 0);
+    mReader->loopOnce();
+    ASSERT_EQ(SECOND_DEVICE_ID, mReader->getLastUsedInputDeviceId());
+}
+
 class FakeVibratorInputMapper : public FakeInputMapper {
 public:
     FakeVibratorInputMapper(InputDeviceContext& deviceContext,
diff --git a/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp b/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp
index 34ea54c..a19726a 100644
--- a/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp
+++ b/services/inputflinger/tests/fuzzers/InputReaderFuzzer.cpp
@@ -169,6 +169,8 @@
         reader->sysfsNodeChanged(sysfsNodePath);
     }
 
+    DeviceId getLastUsedInputDeviceId() override { return reader->getLastUsedInputDeviceId(); }
+
 private:
     std::unique_ptr<InputReaderInterface> reader;
 };