diff --git a/libs/gui/WindowInfo.cpp b/libs/gui/WindowInfo.cpp
index 6df9ff1..cd9b424 100644
--- a/libs/gui/WindowInfo.cpp
+++ b/libs/gui/WindowInfo.cpp
@@ -90,8 +90,9 @@
     }
     parcel->writeInt32(1);
 
-    // Ensure that the size of the flags that we use is 32 bits for writing into the parcel.
+    // Ensure that the size of custom types are what we expect for writing into the parcel.
     static_assert(sizeof(inputConfig) == 4u);
+    static_assert(sizeof(ownerUid.val()) == 4u);
 
     // clang-format off
     status_t status = parcel->writeStrongBinder(token) ?:
@@ -116,7 +117,7 @@
         parcel->writeFloat(transform.ty()) ?:
         parcel->writeInt32(static_cast<int32_t>(touchOcclusionMode)) ?:
         parcel->writeInt32(ownerPid) ?:
-        parcel->writeInt32(ownerUid) ?:
+        parcel->writeInt32(ownerUid.val()) ?:
         parcel->writeUtf8AsUtf16(packageName) ?:
         parcel->writeInt32(inputConfig.get()) ?:
         parcel->writeInt32(displayId) ?:
@@ -147,7 +148,7 @@
     }
 
     float dsdx, dtdx, tx, dtdy, dsdy, ty;
-    int32_t lpFlags, lpType, touchOcclusionModeInt, inputConfigInt;
+    int32_t lpFlags, lpType, touchOcclusionModeInt, inputConfigInt, ownerUidInt;
     sp<IBinder> touchableRegionCropHandleSp;
 
     // clang-format off
@@ -168,7 +169,7 @@
         parcel->readFloat(&ty) ?:
         parcel->readInt32(&touchOcclusionModeInt) ?:
         parcel->readInt32(&ownerPid) ?:
-        parcel->readInt32(&ownerUid) ?:
+        parcel->readInt32(&ownerUidInt) ?:
         parcel->readUtf8FromUtf16(&packageName) ?:
         parcel->readInt32(&inputConfigInt) ?:
         parcel->readInt32(&displayId) ?:
@@ -190,6 +191,7 @@
     transform.set({dsdx, dtdx, tx, dtdy, dsdy, ty, 0, 0, 1});
     touchOcclusionMode = static_cast<TouchOcclusionMode>(touchOcclusionModeInt);
     inputConfig = ftl::Flags<InputConfig>(inputConfigInt);
+    ownerUid = Uid{static_cast<uid_t>(ownerUidInt)};
     touchableRegionCropHandle = touchableRegionCropHandleSp;
 
     return OK;
diff --git a/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp b/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp
index 57720dd..7268e64 100644
--- a/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp
+++ b/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp
@@ -187,7 +187,7 @@
     windowInfo->replaceTouchableRegionWithCrop = mFdp.ConsumeBool();
     windowInfo->touchOcclusionMode = mFdp.PickValueInArray(kMode);
     windowInfo->ownerPid = mFdp.ConsumeIntegral<int32_t>();
-    windowInfo->ownerUid = mFdp.ConsumeIntegral<int32_t>();
+    windowInfo->ownerUid = gui::Uid{mFdp.ConsumeIntegral<uid_t>()};
     windowInfo->packageName = mFdp.ConsumeRandomLengthString(kRandomStringMaxBytes);
     windowInfo->inputConfig = mFdp.PickValueInArray(kFeatures);
 }
diff --git a/libs/gui/include/gui/Uid.h b/libs/gui/include/gui/Uid.h
new file mode 100644
index 0000000..8e45ef5
--- /dev/null
+++ b/libs/gui/include/gui/Uid.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2023 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.
+ */
+
+#pragma once
+
+#include <ftl/mixins.h>
+#include <sys/types.h>
+#include <string>
+
+namespace android::gui {
+
+// Type-safe wrapper for a UID.
+// We treat the unsigned equivalent of -1 as a singular invalid value.
+struct Uid : ftl::Constructible<Uid, uid_t>, ftl::Equatable<Uid>, ftl::Orderable<Uid> {
+    using Constructible::Constructible;
+
+    const static Uid INVALID;
+
+    constexpr auto val() const { return ftl::to_underlying(*this); }
+
+    constexpr bool isValid() const { return val() != static_cast<uid_t>(-1); }
+
+    std::string toString() const { return std::to_string(val()); }
+};
+
+const inline Uid Uid::INVALID{static_cast<uid_t>(-1)};
+
+} // namespace android::gui
diff --git a/libs/gui/include/gui/WindowInfo.h b/libs/gui/include/gui/WindowInfo.h
index 70b2ee8..666101e 100644
--- a/libs/gui/include/gui/WindowInfo.h
+++ b/libs/gui/include/gui/WindowInfo.h
@@ -21,6 +21,8 @@
 #include <binder/Parcel.h>
 #include <binder/Parcelable.h>
 #include <ftl/flags.h>
+#include <ftl/mixins.h>
+#include <gui/Uid.h>
 #include <gui/constants.h>
 #include <ui/Rect.h>
 #include <ui/Region.h>
@@ -224,7 +226,7 @@
 
     TouchOcclusionMode touchOcclusionMode = TouchOcclusionMode::BLOCK_UNTRUSTED;
     int32_t ownerPid = -1;
-    int32_t ownerUid = -1;
+    Uid ownerUid = Uid::INVALID;
     std::string packageName;
     ftl::Flags<InputConfig> inputConfig;
     int32_t displayId = ADISPLAY_ID_NONE;
diff --git a/libs/gui/tests/EndToEndNativeInputTest.cpp b/libs/gui/tests/EndToEndNativeInputTest.cpp
index 4ec7a06..4d5bd5b 100644
--- a/libs/gui/tests/EndToEndNativeInputTest.cpp
+++ b/libs/gui/tests/EndToEndNativeInputTest.cpp
@@ -821,7 +821,7 @@
     // with flag AMOTION_EVENT_FLAG_WINDOW_IS_OBSCURED
     std::unique_ptr<InputSurface> nonTouchableSurface = makeSurface(100, 100);
     nonTouchableSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    nonTouchableSurface->mInputInfo.ownerUid = 22222;
+    nonTouchableSurface->mInputInfo.ownerUid = gui::Uid{22222};
     // Overriding occlusion mode otherwise the touch would be discarded at InputDispatcher by
     // the default obscured/untrusted touch filter introduced in S.
     nonTouchableSurface->mInputInfo.touchOcclusionMode = TouchOcclusionMode::ALLOW;
@@ -842,8 +842,8 @@
     std::unique_ptr<InputSurface> nonTouchableSurface = makeSurface(100, 100);
     nonTouchableSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
     parentSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    nonTouchableSurface->mInputInfo.ownerUid = 22222;
-    parentSurface->mInputInfo.ownerUid = 22222;
+    nonTouchableSurface->mInputInfo.ownerUid = gui::Uid{22222};
+    parentSurface->mInputInfo.ownerUid = gui::Uid{22222};
     nonTouchableSurface->showAt(0, 0);
     parentSurface->showAt(100, 100);
 
@@ -866,8 +866,8 @@
     std::unique_ptr<InputSurface> nonTouchableSurface = makeSurface(100, 100);
     nonTouchableSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
     parentSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    nonTouchableSurface->mInputInfo.ownerUid = 22222;
-    parentSurface->mInputInfo.ownerUid = 22222;
+    nonTouchableSurface->mInputInfo.ownerUid = gui::Uid{22222};
+    parentSurface->mInputInfo.ownerUid = gui::Uid{22222};
     nonTouchableSurface->showAt(0, 0);
     parentSurface->showAt(50, 50);
 
@@ -886,7 +886,7 @@
     std::unique_ptr<InputSurface> bufferSurface =
             InputSurface::makeBufferInputSurface(mComposerClient, 0, 0);
     bufferSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    bufferSurface->mInputInfo.ownerUid = 22222;
+    bufferSurface->mInputInfo.ownerUid = gui::Uid{22222};
 
     surface->showAt(10, 10);
     bufferSurface->showAt(50, 50, Rect::EMPTY_RECT);
@@ -901,7 +901,7 @@
     std::unique_ptr<BlastInputSurface> bufferSurface =
             BlastInputSurface::makeBlastInputSurface(mComposerClient, 0, 0);
     bufferSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    bufferSurface->mInputInfo.ownerUid = 22222;
+    bufferSurface->mInputInfo.ownerUid = gui::Uid{22222};
 
     surface->showAt(10, 10);
     bufferSurface->showAt(50, 50, Rect::EMPTY_RECT);
@@ -948,13 +948,13 @@
 
 TEST_F(InputSurfacesTest, strict_unobscured_input_obscured_window) {
     std::unique_ptr<InputSurface> surface = makeSurface(100, 100);
-    surface->mInputInfo.ownerUid = 11111;
+    surface->mInputInfo.ownerUid = gui::Uid{11111};
     surface->doTransaction(
             [&](auto &t, auto &sc) { t.setDropInputMode(sc, gui::DropInputMode::OBSCURED); });
     surface->showAt(100, 100);
     std::unique_ptr<InputSurface> obscuringSurface = makeSurface(100, 100);
     obscuringSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    obscuringSurface->mInputInfo.ownerUid = 22222;
+    obscuringSurface->mInputInfo.ownerUid = gui::Uid{22222};
     obscuringSurface->showAt(100, 100);
     injectTap(101, 101);
     EXPECT_EQ(surface->consumeEvent(100), nullptr);
@@ -967,13 +967,13 @@
 
 TEST_F(InputSurfacesTest, strict_unobscured_input_partially_obscured_window) {
     std::unique_ptr<InputSurface> surface = makeSurface(100, 100);
-    surface->mInputInfo.ownerUid = 11111;
+    surface->mInputInfo.ownerUid = gui::Uid{11111};
     surface->doTransaction(
             [&](auto &t, auto &sc) { t.setDropInputMode(sc, gui::DropInputMode::OBSCURED); });
     surface->showAt(100, 100);
     std::unique_ptr<InputSurface> obscuringSurface = makeSurface(100, 100);
     obscuringSurface->mInputInfo.setInputConfig(WindowInfo::InputConfig::NOT_TOUCHABLE, true);
-    obscuringSurface->mInputInfo.ownerUid = 22222;
+    obscuringSurface->mInputInfo.ownerUid = gui::Uid{22222};
     obscuringSurface->showAt(190, 190);
 
     injectTap(101, 101);
diff --git a/libs/gui/tests/WindowInfo_test.cpp b/libs/gui/tests/WindowInfo_test.cpp
index 11b87ef..e3a629e 100644
--- a/libs/gui/tests/WindowInfo_test.cpp
+++ b/libs/gui/tests/WindowInfo_test.cpp
@@ -62,7 +62,7 @@
     i.transform.set({0.4, -1, 100, 0.5, 0, 40, 0, 0, 1});
     i.touchOcclusionMode = TouchOcclusionMode::ALLOW;
     i.ownerPid = 19;
-    i.ownerUid = 24;
+    i.ownerUid = gui::Uid{24};
     i.packageName = "com.example.package";
     i.inputConfig = WindowInfo::InputConfig::NOT_FOCUSABLE;
     i.displayId = 34;