diff --git a/generator/dawn_json_generator.py b/generator/dawn_json_generator.py
index 4932e42..8ffa894 100644
--- a/generator/dawn_json_generator.py
+++ b/generator/dawn_json_generator.py
@@ -965,8 +965,7 @@
         if x.category == 'enum':
             return 'i'
         elif x.category == 'bitmask':
-            # TODO(crbug.com/347732150): Change to 'j' when bitmasks are 64-bit
-            return 'i'
+            return 'j'
         elif x.category in ['object', 'function pointer']:
             return 'p'
         elif x.category == 'native':
diff --git a/third_party/emdawnwebgpu/library_webgpu.js b/third_party/emdawnwebgpu/library_webgpu.js
index f7a1594..b467d15 100644
--- a/third_party/emdawnwebgpu/library_webgpu.js
+++ b/third_party/emdawnwebgpu/library_webgpu.js
@@ -703,7 +703,9 @@
 
       // Set up device lost promise resolution.
       if (hasDeviceLostFutureId) {
+        {{{ runtimeKeepalivePush() }}}
         WebGPU._futureInsert(deviceLostFutureIdL, deviceLostFutureIdH, device.lost.then((info) => {
+          {{{ runtimeKeepalivePop() }}}
           // Unset the uncaptured error handler.
           device.onuncapturederror = (ev) => {};
           withStackSave(() => {
diff --git a/third_party/emdawnwebgpu/webgpu.cpp b/third_party/emdawnwebgpu/webgpu.cpp
index 1252d04..9933fe7 100644
--- a/third_party/emdawnwebgpu/webgpu.cpp
+++ b/third_party/emdawnwebgpu/webgpu.cpp
@@ -84,7 +84,9 @@
   static constexpr bool HasExternalRefCount = false;
 
   void AddRef() {
-    assert(mRefCount.fetch_add(1u, std::memory_order_relaxed) >= 1);
+    [[maybe_unused]] uint64_t oldRefCount =
+        mRefCount.fetch_add(1u, std::memory_order_relaxed);
+    assert(oldRefCount >= 1);
   }
 
   void Release() {
@@ -135,11 +137,7 @@
                 "Cannot make a Ref<T> when T is not a Refcounted type.");
 
   Ref() : mValue(nullptr) {}
-  ~Ref() {
-    if (mValue) {
-      mValue->Release();
-    }
-  }
+  ~Ref() { Release(mValue); }
 
   // Constructors from nullptr.
   // NOLINTNEXTLINE(runtime/explicit)