diff --git a/src/dawn/dawn.json b/src/dawn/dawn.json
index fd97565..fde2e91 100644
--- a/src/dawn/dawn.json
+++ b/src/dawn/dawn.json
@@ -1544,6 +1544,7 @@
         "category": "enum",
         "emscripten_no_enum_table": true,
         "values": [
+            {"value": 0, "name": "undefined", "jsrepr": "undefined"},
             {"value": 1, "name": "unknown"},
             {"value": 2, "name": "destroyed"},
             {"value": 3, "name": "instance dropped"},
diff --git a/src/dawn/native/Device.h b/src/dawn/native/Device.h
index d8b014d..5e2462c 100644
--- a/src/dawn/native/Device.h
+++ b/src/dawn/native/Device.h
@@ -126,7 +126,7 @@
     // users as the respective error rather than causing a device loss instead.
     void HandleError(std::unique_ptr<ErrorData> error,
                      InternalErrorType additionalAllowedErrors = InternalErrorType::None,
-                     WGPUDeviceLostReason lost_reason = WGPUDeviceLostReason_Unknown);
+                     WGPUDeviceLostReason lost_reason = WGPUDeviceLostReason_Undefined);
 
     MaybeError ValidateObject(const ApiObjectBase* object) const;
 
diff --git a/src/dawn/node/binding/GPUDevice.cpp b/src/dawn/node/binding/GPUDevice.cpp
index de9184c..c0fcc0d 100644
--- a/src/dawn/node/binding/GPUDevice.cpp
+++ b/src/dawn/node/binding/GPUDevice.cpp
@@ -187,6 +187,7 @@
                 case WGPUDeviceLostReason_InstanceDropped:
                     UNREACHABLE("WGPUDeviceLostReason_InstanceDropped");
                     break;
+                case WGPUDeviceLostReason_Undefined:
                 case WGPUDeviceLostReason_Unknown:
                     r = interop::GPUDeviceLostReason::kUnknown;
                     break;
diff --git a/src/dawn/tests/DawnTest.cpp b/src/dawn/tests/DawnTest.cpp
index 0fbfa98..ab646d7 100644
--- a/src/dawn/tests/DawnTest.cpp
+++ b/src/dawn/tests/DawnTest.cpp
@@ -1234,8 +1234,8 @@
         resolvedDevice = device;
     }
 
-    EXPECT_CALL(mDeviceLostCallback, Call(_, WGPUDeviceLostReason_Unknown, _, _)).Times(1);
-    resolvedDevice.ForceLoss(wgpu::DeviceLostReason::Unknown, "Device lost for testing");
+    EXPECT_CALL(mDeviceLostCallback, Call(_, WGPUDeviceLostReason_Undefined, _, _)).Times(1);
+    resolvedDevice.ForceLoss(wgpu::DeviceLostReason::Undefined, "Device lost for testing");
     resolvedDevice.Tick();
 }
 
diff --git a/src/dawn/tests/benchmarks/NullDeviceSetup.cpp b/src/dawn/tests/benchmarks/NullDeviceSetup.cpp
index 2a894c1..203508c 100644
--- a/src/dawn/tests/benchmarks/NullDeviceSetup.cpp
+++ b/src/dawn/tests/benchmarks/NullDeviceSetup.cpp
@@ -80,7 +80,7 @@
 
             device.SetDeviceLostCallback(
                 [](WGPUDeviceLostReason reason, char const* message, void* userdata) {
-                    if (reason == WGPUDeviceLostReason_Unknown) {
+                    if (reason == WGPUDeviceLostReason_Undefined) {
                         dawn::ErrorLog() << message;
                         DAWN_UNREACHABLE();
                     }
diff --git a/src/dawn/tests/end2end/DeviceLostTests.cpp b/src/dawn/tests/end2end/DeviceLostTests.cpp
index 26837bb..37dba76 100644
--- a/src/dawn/tests/end2end/DeviceLostTests.cpp
+++ b/src/dawn/tests/end2end/DeviceLostTests.cpp
@@ -436,7 +436,7 @@
     // First LoseDeviceForTesting call should occur normally. The callback is already set in SetUp.
     LoseDeviceForTesting();
 
-    device.ForceLoss(wgpu::DeviceLostReason::Unknown, "Device lost for testing");
+    device.ForceLoss(wgpu::DeviceLostReason::Undefined, "Device lost for testing");
     FlushWire();
     testing::Mock::VerifyAndClearExpectations(&mDeviceLostCallback);
 }
diff --git a/src/dawn/tests/end2end/EventTests.cpp b/src/dawn/tests/end2end/EventTests.cpp
index 4f8e15a..f0b5abf 100644
--- a/src/dawn/tests/end2end/EventTests.cpp
+++ b/src/dawn/tests/end2end/EventTests.cpp
@@ -152,9 +152,9 @@
 
     void LoseTestDevice() {
         EXPECT_CALL(mDeviceLostCallback,
-                    Call(testing::_, WGPUDeviceLostReason_Unknown, testing::_, testing::_))
+                    Call(testing::_, WGPUDeviceLostReason_Undefined, testing::_, testing::_))
             .Times(1);
-        testDevice.ForceLoss(wgpu::DeviceLostReason::Unknown, "Device lost for testing");
+        testDevice.ForceLoss(wgpu::DeviceLostReason::Undefined, "Device lost for testing");
         testInstance.ProcessEvents();
     }
 
diff --git a/src/dawn/tests/unittests/native/AllowedErrorTests.cpp b/src/dawn/tests/unittests/native/AllowedErrorTests.cpp
index 6a5b15da..584f109 100644
--- a/src/dawn/tests/unittests/native/AllowedErrorTests.cpp
+++ b/src/dawn/tests/unittests/native/AllowedErrorTests.cpp
@@ -94,7 +94,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
 
     device.GetQueue().Submit(0, nullptr);
@@ -112,7 +112,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
 
     constexpr uint8_t data = 8;
@@ -133,7 +133,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
 
     constexpr uint8_t data[] = {1, 2, 4, 8};
@@ -166,7 +166,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
     device.GetQueue().CopyTextureForBrowser(&src, &dst, &size, &options);
 }
@@ -207,7 +207,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
     device.GetQueue().CopyExternalTextureForBrowser(&src, &dst, &size, &options);
 }
@@ -227,7 +227,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
     device.CreateComputePipeline(ToCppAPI(&desc));
 }
@@ -247,7 +247,7 @@
 
     // Expect the device lost because of the error.
     EXPECT_CALL(mDeviceLostCb,
-                Call(WGPUDeviceLostReason_Unknown, HasSubstr(kOomErrorMessage), this))
+                Call(WGPUDeviceLostReason_Undefined, HasSubstr(kOomErrorMessage), this))
         .Times(1);
     device.CreateRenderPipeline(ToCppAPI(&desc));
 }
diff --git a/src/dawn/tests/unittests/wire/WireDisconnectTests.cpp b/src/dawn/tests/unittests/wire/WireDisconnectTests.cpp
index 7b6ebe0..dc9a06d 100644
--- a/src/dawn/tests/unittests/wire/WireDisconnectTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireDisconnectTests.cpp
@@ -91,12 +91,12 @@
 // Check that disconnecting the wire client after a device loss does not trigger the callback
 // again.
 TEST_F(WireDisconnectTests, ServerLostThenDisconnect) {
-    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Unknown,
+    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Undefined,
                                                 "some reason");
 
     // Flush the device lost return command.
     EXPECT_CALL(deviceLostCallback,
-                Call(_, WGPUDeviceLostReason_Unknown, StrEq("some reason"), this))
+                Call(_, WGPUDeviceLostReason_Undefined, StrEq("some reason"), this))
         .Times(Exactly(1));
     FlushServer();
 
@@ -112,13 +112,13 @@
     wgpuDeviceSetDeviceLostCallback(device, mockDeviceLostCallback.Callback(),
                                     mockDeviceLostCallback.MakeUserdata(this));
 
-    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Unknown,
+    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Undefined,
                                                 "lost reason");
 
     // Disconnect the client inside the lost callback. We should see the callback
     // only once.
     EXPECT_CALL(mockDeviceLostCallback,
-                Call(WGPUDeviceLostReason_Unknown, StrEq("lost reason"), this))
+                Call(WGPUDeviceLostReason_Undefined, StrEq("lost reason"), this))
         .WillOnce(InvokeWithoutArgs([&] {
             EXPECT_CALL(mockDeviceLostCallback, Call(_, _, _)).Times(Exactly(0));
             GetWireClient()->Disconnect();
@@ -139,7 +139,7 @@
 
     // Lose the device on the server. The client callback shouldn't be
     // called again.
-    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Unknown,
+    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Undefined,
                                                 "lost reason");
     EXPECT_CALL(mockDeviceLostCallback, Call(_, _, _)).Times(Exactly(0));
     FlushServer();
diff --git a/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp b/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp
index 2a91393..a1f52c2 100644
--- a/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp
+++ b/src/dawn/tests/unittests/wire/WireErrorCallbackTests.cpp
@@ -187,11 +187,11 @@
 
     // Calling the callback on the server side will result in the callback being called on the
     // client side
-    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Unknown,
+    api.CallDeviceSetDeviceLostCallbackCallback(apiDevice, WGPUDeviceLostReason_Undefined,
                                                 "Some error message");
 
     EXPECT_CALL(*mockDeviceLostCallback,
-                Call(WGPUDeviceLostReason_Unknown, StrEq("Some error message"), this))
+                Call(WGPUDeviceLostReason_Undefined, StrEq("Some error message"), this))
         .Times(1);
 
     FlushServer();
diff --git a/src/dawn/wire/client/Client.cpp b/src/dawn/wire/client/Client.cpp
index bacb0f1..3cc08d6 100644
--- a/src/dawn/wire/client/Client.cpp
+++ b/src/dawn/wire/client/Client.cpp
@@ -187,7 +187,7 @@
         for (LinkNode<ObjectBase>* device = deviceList.head(); device != deviceList.end();
              device = device->next()) {
             static_cast<Device*>(device->value())
-                ->HandleDeviceLost(WGPUDeviceLostReason_Unknown, "GPU connection lost");
+                ->HandleDeviceLost(WGPUDeviceLostReason_Undefined, "GPU connection lost");
         }
     }
     for (auto& objectList : mObjects) {