diff --git a/plume_d3d12.cpp b/plume_d3d12.cpp
index 2cdcf18..5e842c5 100644
--- a/plume_d3d12.cpp
+++ b/plume_d3d12.cpp
@@ -879,7 +879,7 @@ namespace plume {
     D3D12_CPU_DESCRIPTOR_HANDLE D3D12DescriptorHeapAllocator::getCPUHandleAt(uint32_t index) const {
         assert(index < heapSize);
         assert(cpuDescriptorHandle.ptr > 0);
-        return { cpuDescriptorHandle.ptr + uint64_t(index) * descriptorHandleIncrement };
+        return { cpuDescriptorHandle.ptr + SIZE_T(index) * descriptorHandleIncrement };
     }
 
     D3D12_GPU_DESCRIPTOR_HANDLE D3D12DescriptorHeapAllocator::getGPUHandleAt(uint32_t index) const {
diff --git a/plume_render_interface_types.h b/plume_render_interface_types.h
index 9dcfedf..2281168 100644
--- a/plume_render_interface_types.h
+++ b/plume_render_interface_types.h
@@ -15,7 +15,7 @@
 #include <cfloat>
 #include <cstdint>
 
-#if defined(_WIN64)
+#if defined(_WIN32)
 #include <Windows.h>
 #elif defined(__ANDROID__)
 #include "android/native_window.h"
@@ -34,7 +34,7 @@
 #endif
 
 namespace plume {
-#if defined(_WIN64)
+#if defined(_WIN32)
     // Native HWND handle to the target window.
     typedef HWND RenderWindow;
 #elif defined(__ANDROID__)
diff --git a/plume_vulkan.cpp b/plume_vulkan.cpp
index f1dd503..4a2a489 100644
--- a/plume_vulkan.cpp
+++ b/plume_vulkan.cpp
@@ -48,7 +48,7 @@ namespace plume {
 #   ifdef VULKAN_OBJECT_NAMES_ENABLED
         VK_EXT_DEBUG_UTILS_EXTENSION_NAME,
 #   endif
-#   if defined(_WIN64)
+#   if defined(_WIN32)
         VK_KHR_WIN32_SURFACE_EXTENSION_NAME,
 #   elif defined(__ANDROID__)
         VK_KHR_ANDROID_SURFACE_EXTENSION_NAME,
@@ -1855,7 +1855,7 @@ namespace plume {
 
         this->descriptorSetCount = uint32_t(pipelineLayout->descriptorSetLayouts.size());
 
-        VkResult res = vkCreateRayTracingPipelinesKHR(device->vk, nullptr, nullptr, 1, &pipelineInfo, nullptr, &vk);
+        VkResult res = vkCreateRayTracingPipelinesKHR(device->vk, VK_NULL_HANDLE, VK_NULL_HANDLE, 1, &pipelineInfo, nullptr, &vk);
         if (res != VK_SUCCESS) {
             fprintf(stderr, "vkCreateRayTracingPipelinesKHR failed with error code 0x%X.\n", res);
             return;
@@ -2082,7 +2082,7 @@ namespace plume {
 
         VkResult res;
 
-#   ifdef _WIN64
+#   if defined(_WIN32)
         assert(desc.renderWindow != 0);
         VkWin32SurfaceCreateInfoKHR surfaceCreateInfo = {};
         surfaceCreateInfo.sType = VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR;
@@ -2458,7 +2458,7 @@ namespace plume {
     }
 
     void VulkanSwapChain::getWindowSize(uint32_t &dstWidth, uint32_t &dstHeight) const {
-#   if defined(_WIN64)
+#   if defined(_WIN32)
         RECT rect;
         GetClientRect(desc.renderWindow, &rect);
         dstWidth = rect.right - rect.left;
diff --git a/plume_vulkan.h b/plume_vulkan.h
index 0a1edbe..a0cf5cc 100644
--- a/plume_vulkan.h
+++ b/plume_vulkan.h
@@ -14,7 +14,7 @@
 #include <unordered_map>
 #include <unordered_set>
 
-#if defined(_WIN64)
+#if defined(_WIN32)
 #define VK_USE_PLATFORM_WIN32_KHR
 #elif defined(__ANDROID__)
 #define VK_USE_PLATFORM_ANDROID_KHR