diff --git a/libs/gui/WindowInfo.cpp b/libs/gui/WindowInfo.cpp
index cd9b424..52af9d5 100644
--- a/libs/gui/WindowInfo.cpp
+++ b/libs/gui/WindowInfo.cpp
@@ -92,6 +92,7 @@
 
     // Ensure that the size of custom types are what we expect for writing into the parcel.
     static_assert(sizeof(inputConfig) == 4u);
+    static_assert(sizeof(ownerPid.val()) == 4u);
     static_assert(sizeof(ownerUid.val()) == 4u);
 
     // clang-format off
@@ -116,7 +117,7 @@
         parcel->writeFloat(transform.dsdy()) ?:
         parcel->writeFloat(transform.ty()) ?:
         parcel->writeInt32(static_cast<int32_t>(touchOcclusionMode)) ?:
-        parcel->writeInt32(ownerPid) ?:
+        parcel->writeInt32(ownerPid.val()) ?:
         parcel->writeInt32(ownerUid.val()) ?:
         parcel->writeUtf8AsUtf16(packageName) ?:
         parcel->writeInt32(inputConfig.get()) ?:
@@ -148,7 +149,7 @@
     }
 
     float dsdx, dtdx, tx, dtdy, dsdy, ty;
-    int32_t lpFlags, lpType, touchOcclusionModeInt, inputConfigInt, ownerUidInt;
+    int32_t lpFlags, lpType, touchOcclusionModeInt, inputConfigInt, ownerPidInt, ownerUidInt;
     sp<IBinder> touchableRegionCropHandleSp;
 
     // clang-format off
@@ -168,7 +169,7 @@
         parcel->readFloat(&dsdy) ?:
         parcel->readFloat(&ty) ?:
         parcel->readInt32(&touchOcclusionModeInt) ?:
-        parcel->readInt32(&ownerPid) ?:
+        parcel->readInt32(&ownerPidInt) ?:
         parcel->readInt32(&ownerUidInt) ?:
         parcel->readUtf8FromUtf16(&packageName) ?:
         parcel->readInt32(&inputConfigInt) ?:
@@ -191,6 +192,7 @@
     transform.set({dsdx, dtdx, tx, dtdy, dsdy, ty, 0, 0, 1});
     touchOcclusionMode = static_cast<TouchOcclusionMode>(touchOcclusionModeInt);
     inputConfig = ftl::Flags<InputConfig>(inputConfigInt);
+    ownerPid = Pid{ownerPidInt};
     ownerUid = Uid{static_cast<uid_t>(ownerUidInt)};
     touchableRegionCropHandle = touchableRegionCropHandleSp;
 
diff --git a/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp b/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp
index 7268e64..95b7f39 100644
--- a/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp
+++ b/libs/gui/fuzzer/libgui_surfaceComposerClient_fuzzer.cpp
@@ -186,7 +186,7 @@
     windowInfo->touchableRegion = Region(getRect(&mFdp));
     windowInfo->replaceTouchableRegionWithCrop = mFdp.ConsumeBool();
     windowInfo->touchOcclusionMode = mFdp.PickValueInArray(kMode);
-    windowInfo->ownerPid = mFdp.ConsumeIntegral<int32_t>();
+    windowInfo->ownerPid = gui::Pid{mFdp.ConsumeIntegral<pid_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/PidUid.h
similarity index 75%
rename from libs/gui/include/gui/Uid.h
rename to libs/gui/include/gui/PidUid.h
index 8e45ef5..7930942 100644
--- a/libs/gui/include/gui/Uid.h
+++ b/libs/gui/include/gui/PidUid.h
@@ -22,6 +22,21 @@
 
 namespace android::gui {
 
+// Type-safe wrapper for a PID.
+struct Pid : ftl::Constructible<Pid, pid_t>, ftl::Equatable<Pid>, ftl::Orderable<Pid> {
+    using Constructible::Constructible;
+
+    const static Pid INVALID;
+
+    constexpr auto val() const { return ftl::to_underlying(*this); }
+
+    constexpr bool isValid() const { return val() >= 0; }
+
+    std::string toString() const { return std::to_string(val()); }
+};
+
+const inline Pid Pid::INVALID{-1};
+
 // 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> {
diff --git a/libs/gui/include/gui/WindowInfo.h b/libs/gui/include/gui/WindowInfo.h
index 666101e..7ff7387 100644
--- a/libs/gui/include/gui/WindowInfo.h
+++ b/libs/gui/include/gui/WindowInfo.h
@@ -22,7 +22,7 @@
 #include <binder/Parcelable.h>
 #include <ftl/flags.h>
 #include <ftl/mixins.h>
-#include <gui/Uid.h>
+#include <gui/PidUid.h>
 #include <gui/constants.h>
 #include <ui/Rect.h>
 #include <ui/Region.h>
@@ -225,7 +225,7 @@
     Region touchableRegion;
 
     TouchOcclusionMode touchOcclusionMode = TouchOcclusionMode::BLOCK_UNTRUSTED;
-    int32_t ownerPid = -1;
+    Pid ownerPid = Pid::INVALID;
     Uid ownerUid = Uid::INVALID;
     std::string packageName;
     ftl::Flags<InputConfig> inputConfig;
diff --git a/libs/gui/tests/WindowInfo_test.cpp b/libs/gui/tests/WindowInfo_test.cpp
index e3a629e..461fe4a 100644
--- a/libs/gui/tests/WindowInfo_test.cpp
+++ b/libs/gui/tests/WindowInfo_test.cpp
@@ -61,7 +61,7 @@
     i.alpha = 0.7;
     i.transform.set({0.4, -1, 100, 0.5, 0, 40, 0, 0, 1});
     i.touchOcclusionMode = TouchOcclusionMode::ALLOW;
-    i.ownerPid = 19;
+    i.ownerPid = gui::Pid{19};
     i.ownerUid = gui::Uid{24};
     i.packageName = "com.example.package";
     i.inputConfig = WindowInfo::InputConfig::NOT_FOCUSABLE;