diff --git a/CMakeLists.txt b/CMakeLists.txt
index e16830aa..202f32f2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,6 +14,7 @@ option(MI_OSX_ZONE          "Use malloc zone to override standard malloc on macO
 option(MI_LOCAL_DYNAMIC_TLS "Use slightly slower, dlopen-compatible TLS mechanism (Unix)" OFF)
 option(MI_BUILD_TESTS       "Build test executables" ON)
 option(MI_CHECK_FULL        "Use full internal invariant checking in DEBUG mode (deprecated, use MI_DEBUG_FULL instead)" OFF)
+option(MI_WIN_NUMA          "Support NUMA aware allocation on Windows" ON)
 
 include("cmake/mimalloc-config-version.cmake")
 
@@ -111,6 +112,11 @@ if(MI_USE_CXX MATCHES "ON")
   endif()
 endif()
 
+if(MI_WIN_NUMA MATCHES "ON")
+  message(STATUS "Support NUMA aware allocation on Windows (MI_WIN_NUMA=ON)")
+  list(APPEND mi_defines MI_WIN_NUMA)
+endif()
+
 # Compiler flags
 if(CMAKE_C_COMPILER_ID MATCHES "AppleClang|Clang|GNU")
   list(APPEND mi_cflags -Wall -Wextra -Wno-unknown-pragmas -fvisibility=hidden)
diff --git a/ide/vs2017/mimalloc-override.vcxproj b/ide/vs2017/mimalloc-override.vcxproj
index 990d6ca9..268c7091 100644
--- a/ide/vs2017/mimalloc-override.vcxproj
+++ b/ide/vs2017/mimalloc-override.vcxproj
@@ -95,7 +95,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <SupportJustMyCode>false</SupportJustMyCode>
       <CompileAs>Default</CompileAs>
@@ -123,7 +123,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <SupportJustMyCode>false</SupportJustMyCode>
       <CompileAs>Default</CompileAs>
@@ -152,7 +152,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
@@ -184,7 +184,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
@@ -251,4 +251,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/ide/vs2017/mimalloc.vcxproj b/ide/vs2017/mimalloc.vcxproj
index 770a87b2..3a95d9cf 100644
--- a/ide/vs2017/mimalloc.vcxproj
+++ b/ide/vs2017/mimalloc.vcxproj
@@ -109,7 +109,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_DEBUG=3;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_DEBUG=3;MI_WIN_NUMA;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <CompileAs>CompileAsCpp</CompileAs>
       <SupportJustMyCode>false</SupportJustMyCode>
       <LanguageStandard>stdcpp17</LanguageStandard>
@@ -128,7 +128,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_DEBUG=3;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_DEBUG=3;MI_WIN_NUMA;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <CompileAs>CompileAsCpp</CompileAs>
       <SupportJustMyCode>false</SupportJustMyCode>
       <LanguageStandard>stdcpp17</LanguageStandard>
@@ -155,7 +155,7 @@
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_WIN_NUMA;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
@@ -182,7 +182,7 @@
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>_CRT_SECURE_NO_WARNINGS;MI_WIN_NUMA;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
@@ -257,4 +257,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>
\ No newline at end of file
diff --git a/ide/vs2019/mimalloc-override.vcxproj b/ide/vs2019/mimalloc-override.vcxproj
index 17b6f4c0..2195663c 100644
--- a/ide/vs2019/mimalloc-override.vcxproj
+++ b/ide/vs2019/mimalloc-override.vcxproj
@@ -95,7 +95,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <SupportJustMyCode>false</SupportJustMyCode>
       <CompileAs>Default</CompileAs>
@@ -123,7 +123,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_DEBUG=3;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_DEBUG=3;MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDebugDLL</RuntimeLibrary>
       <SupportJustMyCode>false</SupportJustMyCode>
       <CompileAs>Default</CompileAs>
@@ -152,7 +152,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
@@ -184,7 +184,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_WIN_NUMA;MI_SHARED_LIB;MI_SHARED_LIB_EXPORT;MI_MALLOC_OVERRIDE;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
diff --git a/ide/vs2019/mimalloc.vcxproj b/ide/vs2019/mimalloc.vcxproj
index e18db0c5..052f4c50 100644
--- a/ide/vs2019/mimalloc.vcxproj
+++ b/ide/vs2019/mimalloc.vcxproj
@@ -97,7 +97,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_DEBUG=3;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_DEBUG=3;MI_WIN_NUMA;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <CompileAs>CompileAsCpp</CompileAs>
       <SupportJustMyCode>false</SupportJustMyCode>
       <LanguageStandard>Default</LanguageStandard>
@@ -116,7 +116,7 @@
       <SDLCheck>true</SDLCheck>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>MI_DEBUG=3;%(PreprocessorDefinitions);</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_DEBUG=3;MI_WIN_NUMA;%(PreprocessorDefinitions);</PreprocessorDefinitions>
       <CompileAs>CompileAsCpp</CompileAs>
       <SupportJustMyCode>false</SupportJustMyCode>
       <LanguageStandard>Default</LanguageStandard>
@@ -143,7 +143,7 @@
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_WIN_NUMA;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
@@ -171,7 +171,7 @@
       <FunctionLevelLinking>true</FunctionLevelLinking>
       <ConformanceMode>true</ConformanceMode>
       <AdditionalIncludeDirectories>../../include</AdditionalIncludeDirectories>
-      <PreprocessorDefinitions>%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
+      <PreprocessorDefinitions>MI_WIN_NUMA;%(PreprocessorDefinitions);NDEBUG</PreprocessorDefinitions>
       <AssemblerOutput>AssemblyAndSourceCode</AssemblerOutput>
       <AssemblerListingLocation>$(IntDir)</AssemblerListingLocation>
       <WholeProgramOptimization>false</WholeProgramOptimization>
diff --git a/src/os.c b/src/os.c
index 0aa85bd6..6b6676f2 100644
--- a/src/os.c
+++ b/src/os.c
@@ -1007,7 +1007,7 @@ void _mi_os_free_huge_pages(void* p, size_t size, mi_stats_t* stats) {
 /* ----------------------------------------------------------------------------
 Support NUMA aware allocation
 -----------------------------------------------------------------------------*/
-#ifdef WIN32
+#if defined(WIN32) && defined(MI_WIN_NUMA)
 static size_t mi_os_numa_nodex() {
   PROCESSOR_NUMBER pnum;
   USHORT numa_node = 0;