diff --git a/src/dawn/common/SystemUtils.cpp b/src/dawn/common/SystemUtils.cpp
index cad35955d6..2e29820728 100644
--- a/src/dawn/common/SystemUtils.cpp
+++ b/src/dawn/common/SystemUtils.cpp
@@ -158,7 +158,7 @@ std::optional<std::string> GetModulePath() {
     }
 
     std::array<char, PATH_MAX> absolutePath;
-    if (realpath(dlInfo.dli_fname, absolutePath.data()) == NULL) {
+    if (realpath(dlInfo.dli_fname, absolutePath.data()) == nullptr) {
         return {};
     }
     return absolutePath.data();
diff --git a/src/dawn/native/d3d12/DeviceD3D12.cpp b/src/dawn/native/d3d12/DeviceD3D12.cpp
index 4a6a1bddae..9bfb03e9cf 100644
--- a/src/dawn/native/d3d12/DeviceD3D12.cpp
+++ b/src/dawn/native/d3d12/DeviceD3D12.cpp
@@ -160,19 +160,19 @@ MaybeError Device::Initialize(const DeviceDescriptor* descriptor) {
     programDesc.NumArgumentDescs = 1;
     programDesc.pArgumentDescs = &argumentDesc;
 
-    GetD3D12Device()->CreateCommandSignature(&programDesc, NULL,
+    GetD3D12Device()->CreateCommandSignature(&programDesc, nullptr,
                                              IID_PPV_ARGS(&mDispatchIndirectSignature));
 
     argumentDesc.Type = D3D12_INDIRECT_ARGUMENT_TYPE_DRAW;
     programDesc.ByteStride = 4 * sizeof(uint32_t);
 
-    GetD3D12Device()->CreateCommandSignature(&programDesc, NULL,
+    GetD3D12Device()->CreateCommandSignature(&programDesc, nullptr,
                                              IID_PPV_ARGS(&mDrawIndirectSignature));
 
     argumentDesc.Type = D3D12_INDIRECT_ARGUMENT_TYPE_DRAW_INDEXED;
     programDesc.ByteStride = 5 * sizeof(uint32_t);
 
-    GetD3D12Device()->CreateCommandSignature(&programDesc, NULL,
+    GetD3D12Device()->CreateCommandSignature(&programDesc, nullptr,
                                              IID_PPV_ARGS(&mDrawIndexedIndirectSignature));
 
     DAWN_TRY(DeviceBase::Initialize(Queue::Create(this, &descriptor->defaultQueue)));
diff --git a/src/dawn/native/vulkan/QuerySetVk.cpp b/src/dawn/native/vulkan/QuerySetVk.cpp
index aa1aac2e7b..3bdb9f7913 100644
--- a/src/dawn/native/vulkan/QuerySetVk.cpp
+++ b/src/dawn/native/vulkan/QuerySetVk.cpp
@@ -76,7 +76,7 @@ ResultOrError<Ref<QuerySet>> QuerySet::Create(Device* device,
 MaybeError QuerySet::Initialize() {
     VkQueryPoolCreateInfo createInfo;
     createInfo.sType = VK_STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO;
-    createInfo.pNext = NULL;
+    createInfo.pNext = nullptr;
     createInfo.flags = 0;
     createInfo.queryType = VulkanQueryType(GetQueryType());
     createInfo.queryCount = std::max(GetQueryCount(), uint32_t(1u));
diff --git a/src/tint/utils/io/command_windows.cc b/src/tint/utils/io/command_windows.cc
index 8c94e254f4..abe724291c 100644
--- a/src/tint/utils/io/command_windows.cc
+++ b/src/tint/utils/io/command_windows.cc
@@ -102,18 +102,18 @@ class Pipe {
 
 /// Queries whether the file at the given path is an executable or DLL.
 bool ExecutableExists(const std::string& path) {
-    auto file = Handle(CreateFileA(path.c_str(), GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING,
-                                   FILE_ATTRIBUTE_READONLY, NULL));
+    auto file = Handle(CreateFileA(path.c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr,
+                                   OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, nullptr));
     if (!file) {
         return false;
     }
 
-    auto map = Handle(CreateFileMappingA(file, NULL, PAGE_READONLY, 0, 0, NULL));
+    auto map = Handle(CreateFileMappingA(file, nullptr, PAGE_READONLY, 0, 0, nullptr));
     if (map == INVALID_HANDLE_VALUE) {
         return false;
     }
 
-    void* addr_header = MapViewOfFileEx(map, FILE_MAP_READ, 0, 0, 0, NULL);
+    void* addr_header = MapViewOfFileEx(map, FILE_MAP_READ, 0, 0, 0, nullptr);
 
     // Dynamically obtain the address of, and call ImageNtHeader. This is done to avoid tint.exe
     // needing to statically link Dbghelp.lib.