diff --git a/include/input/DisplayViewport.h b/include/input/DisplayViewport.h
index b0eceef..97c2ab8 100644
--- a/include/input/DisplayViewport.h
+++ b/include/input/DisplayViewport.h
@@ -19,7 +19,6 @@
 #include <android-base/stringprintf.h>
 #include <ftl/enum.h>
 #include <ftl/string.h>
-#include <gui/constants.h>
 #include <input/Input.h>
 #include <ui/Rotation.h>
 
@@ -47,7 +46,7 @@
  * See com.android.server.display.DisplayViewport.
  */
 struct DisplayViewport {
-    int32_t displayId; // -1 if invalid
+    ui::LogicalDisplayId displayId; // ADISPLAY_ID_NONE if invalid
     ui::Rotation orientation;
     int32_t logicalLeft;
     int32_t logicalTop;
@@ -67,7 +66,7 @@
     ViewportType type;
 
     DisplayViewport()
-          : displayId(ADISPLAY_ID_NONE),
+          : displayId(ui::ADISPLAY_ID_NONE),
             orientation(ui::ROTATION_0),
             logicalLeft(0),
             logicalTop(0),
@@ -99,12 +98,10 @@
         return !(*this == other);
     }
 
-    inline bool isValid() const {
-        return displayId >= 0;
-    }
+    inline bool isValid() const { return displayId.isValid(); }
 
     void setNonDisplayViewport(int32_t width, int32_t height) {
-        displayId = ADISPLAY_ID_NONE;
+        displayId = ui::ADISPLAY_ID_NONE;
         orientation = ui::ROTATION_0;
         logicalLeft = 0;
         logicalTop = 0;
@@ -123,12 +120,13 @@
     }
 
     std::string toString() const {
-        return StringPrintf("Viewport %s: displayId=%d, uniqueId=%s, port=%s, orientation=%d, "
+        return StringPrintf("Viewport %s: displayId=%s, uniqueId=%s, port=%s, orientation=%d, "
                             "logicalFrame=[%d, %d, %d, %d], "
                             "physicalFrame=[%d, %d, %d, %d], "
                             "deviceSize=[%d, %d], "
                             "isActive=[%d]",
-                            ftl::enum_string(type).c_str(), displayId, uniqueId.c_str(),
+                            ftl::enum_string(type).c_str(), displayId.toString().c_str(),
+                            uniqueId.c_str(),
                             physicalPort ? ftl::to_string(*physicalPort).c_str() : "<none>",
                             static_cast<int>(orientation), logicalLeft, logicalTop, logicalRight,
                             logicalBottom, physicalLeft, physicalTop, physicalRight, physicalBottom,
diff --git a/include/input/Input.h b/include/input/Input.h
index 3f81fb0..092a698 100644
--- a/include/input/Input.h
+++ b/include/input/Input.h
@@ -29,6 +29,7 @@
 #include <android/os/PointerIconType.h>
 #include <math.h>
 #include <stdint.h>
+#include <ui/LogicalDisplayId.h>
 #include <ui/Transform.h>
 #include <utils/BitSet.h>
 #include <utils/Timers.h>
@@ -547,9 +548,9 @@
 
     inline void setSource(uint32_t source) { mSource = source; }
 
-    inline int32_t getDisplayId() const { return mDisplayId; }
+    inline ui::LogicalDisplayId getDisplayId() const { return mDisplayId; }
 
-    inline void setDisplayId(int32_t displayId) { mDisplayId = displayId; }
+    inline void setDisplayId(ui::LogicalDisplayId displayId) { mDisplayId = displayId; }
 
     inline std::array<uint8_t, 32> getHmac() const { return mHmac; }
 
@@ -558,7 +559,7 @@
     bool operator==(const InputEvent&) const = default;
 
 protected:
-    void initialize(int32_t id, DeviceId deviceId, uint32_t source, int32_t displayId,
+    void initialize(int32_t id, DeviceId deviceId, uint32_t source, ui::LogicalDisplayId displayId,
                     std::array<uint8_t, 32> hmac);
 
     void initialize(const InputEvent& from);
@@ -566,7 +567,7 @@
     int32_t mId;
     DeviceId mDeviceId;
     uint32_t mSource;
-    int32_t mDisplayId;
+    ui::LogicalDisplayId mDisplayId{ui::ADISPLAY_ID_NONE};
     std::array<uint8_t, 32> mHmac;
 };
 
@@ -602,7 +603,7 @@
     static const char* getLabel(int32_t keyCode);
     static std::optional<int> getKeyCodeFromLabel(const char* label);
 
-    void initialize(int32_t id, DeviceId deviceId, uint32_t source, int32_t displayId,
+    void initialize(int32_t id, DeviceId deviceId, uint32_t source, ui::LogicalDisplayId displayId,
                     std::array<uint8_t, 32> hmac, int32_t action, int32_t flags, int32_t keyCode,
                     int32_t scanCode, int32_t metaState, int32_t repeatCount, nsecs_t downTime,
                     nsecs_t eventTime);
@@ -864,7 +865,7 @@
 
     ssize_t findPointerIndex(int32_t pointerId) const;
 
-    void initialize(int32_t id, DeviceId deviceId, uint32_t source, int32_t displayId,
+    void initialize(int32_t id, DeviceId deviceId, uint32_t source, ui::LogicalDisplayId displayId,
                     std::array<uint8_t, 32> hmac, int32_t action, int32_t actionButton,
                     int32_t flags, int32_t edgeFlags, int32_t metaState, int32_t buttonState,
                     MotionClassification classification, const ui::Transform& transform,
@@ -1073,7 +1074,7 @@
     DeviceId deviceId;
     nsecs_t eventTimeNanos;
     uint32_t source;
-    int32_t displayId;
+    ui::LogicalDisplayId displayId;
 };
 
 /**
diff --git a/include/input/InputDevice.h b/include/input/InputDevice.h
index e93fe8c..8783d9c 100644
--- a/include/input/InputDevice.h
+++ b/include/input/InputDevice.h
@@ -280,7 +280,7 @@
 
     void initialize(int32_t id, int32_t generation, int32_t controllerNumber,
                     const InputDeviceIdentifier& identifier, const std::string& alias,
-                    bool isExternal, bool hasMic, int32_t associatedDisplayId,
+                    bool isExternal, bool hasMic, ui::LogicalDisplayId associatedDisplayId,
                     InputDeviceViewBehavior viewBehavior = {{}}, bool enabled = true);
 
     inline int32_t getId() const { return mId; }
@@ -348,7 +348,7 @@
     }
     inline std::optional<InputDeviceUsiVersion> getUsiVersion() const { return mUsiVersion; }
 
-    inline int32_t getAssociatedDisplayId() const { return mAssociatedDisplayId; }
+    inline ui::LogicalDisplayId getAssociatedDisplayId() const { return mAssociatedDisplayId; }
 
     inline void setEnabled(bool enabled) { mEnabled = enabled; }
     inline bool isEnabled() const { return mEnabled; }
@@ -366,7 +366,7 @@
     int32_t mKeyboardType;
     std::shared_ptr<KeyCharacterMap> mKeyCharacterMap;
     std::optional<InputDeviceUsiVersion> mUsiVersion;
-    int32_t mAssociatedDisplayId;
+    ui::LogicalDisplayId mAssociatedDisplayId{ui::ADISPLAY_ID_NONE};
     bool mEnabled;
 
     bool mHasVibrator;
diff --git a/include/input/InputEventBuilders.h b/include/input/InputEventBuilders.h
index c0c5e24..837e70e 100644
--- a/include/input/InputEventBuilders.h
+++ b/include/input/InputEventBuilders.h
@@ -18,7 +18,6 @@
 
 #include <android/input.h>
 #include <attestation/HmacKeyManager.h>
-#include <gui/constants.h>
 #include <input/Input.h>
 #include <utils/Timers.h> // for nsecs_t, systemTime
 
@@ -83,7 +82,7 @@
         return *this;
     }
 
-    MotionEventBuilder& displayId(int32_t displayId) {
+    MotionEventBuilder& displayId(ui::LogicalDisplayId displayId) {
         mDisplayId = displayId;
         return *this;
     }
@@ -159,7 +158,7 @@
     int32_t mSource;
     nsecs_t mDownTime;
     nsecs_t mEventTime;
-    int32_t mDisplayId{ADISPLAY_ID_DEFAULT};
+    ui::LogicalDisplayId mDisplayId{ui::ADISPLAY_ID_DEFAULT};
     int32_t mActionButton{0};
     int32_t mButtonState{0};
     int32_t mFlags{0};
@@ -209,7 +208,7 @@
         return *this;
     }
 
-    KeyEventBuilder& displayId(int32_t displayId) {
+    KeyEventBuilder& displayId(ui::LogicalDisplayId displayId) {
         mDisplayId = displayId;
         return *this;
     }
@@ -248,7 +247,7 @@
     uint32_t mSource;
     nsecs_t mDownTime;
     nsecs_t mEventTime;
-    int32_t mDisplayId{ADISPLAY_ID_DEFAULT};
+    ui::LogicalDisplayId mDisplayId{ui::ADISPLAY_ID_DEFAULT};
     uint32_t mPolicyFlags = DEFAULT_POLICY_FLAGS;
     int32_t mFlags{0};
     int32_t mKeyCode{AKEYCODE_UNKNOWN};
diff --git a/include/input/InputTransport.h b/include/input/InputTransport.h
index 5f9c8f5..6548810 100644
--- a/include/input/InputTransport.h
+++ b/include/input/InputTransport.h
@@ -353,9 +353,10 @@
      * Other errors probably indicate that the channel is broken.
      */
     status_t publishKeyEvent(uint32_t seq, int32_t eventId, int32_t deviceId, int32_t source,
-                             int32_t displayId, std::array<uint8_t, 32> hmac, int32_t action,
-                             int32_t flags, int32_t keyCode, int32_t scanCode, int32_t metaState,
-                             int32_t repeatCount, nsecs_t downTime, nsecs_t eventTime);
+                             ui::LogicalDisplayId displayId, std::array<uint8_t, 32> hmac,
+                             int32_t action, int32_t flags, int32_t keyCode, int32_t scanCode,
+                             int32_t metaState, int32_t repeatCount, nsecs_t downTime,
+                             nsecs_t eventTime);
 
     /* Publishes a motion event to the input channel.
      *
@@ -366,9 +367,9 @@
      * Other errors probably indicate that the channel is broken.
      */
     status_t publishMotionEvent(uint32_t seq, int32_t eventId, int32_t deviceId, int32_t source,
-                                int32_t displayId, std::array<uint8_t, 32> hmac, int32_t action,
-                                int32_t actionButton, int32_t flags, int32_t edgeFlags,
-                                int32_t metaState, int32_t buttonState,
+                                ui::LogicalDisplayId displayId, std::array<uint8_t, 32> hmac,
+                                int32_t action, int32_t actionButton, int32_t flags,
+                                int32_t edgeFlags, int32_t metaState, int32_t buttonState,
                                 MotionClassification classification, const ui::Transform& transform,
                                 float xPrecision, float yPrecision, float xCursorPosition,
                                 float yCursorPosition, const ui::Transform& rawTransform,