diff --git a/CMakeLists.txt b/CMakeLists.txt
index a3acf83e..058cb1d9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -749,13 +749,10 @@ if (MI_OVERRIDE)
   if (MI_BUILD_SHARED)
     target_compile_definitions(mimalloc PRIVATE MI_MALLOC_OVERRIDE)
   endif()
-  if(NOT WIN32)
-    # It is only possible to override malloc on Windows when building as a DLL.
-    if (MI_BUILD_STATIC)
-      target_compile_definitions(mimalloc-static PRIVATE MI_MALLOC_OVERRIDE)
-    endif()
-    if (MI_BUILD_OBJECT)
-      target_compile_definitions(mimalloc-obj PRIVATE MI_MALLOC_OVERRIDE)
-    endif()
+  if (MI_BUILD_STATIC)
+    target_compile_definitions(mimalloc-static PRIVATE MI_MALLOC_OVERRIDE)
+  endif()
+  if (MI_BUILD_OBJECT)
+    target_compile_definitions(mimalloc-obj PRIVATE MI_MALLOC_OVERRIDE)
   endif()
 endif()
diff --git a/src/alloc-override.c b/src/alloc-override.c
index b5109ded..6ee5f2bf 100644
--- a/src/alloc-override.c
+++ b/src/alloc-override.c
@@ -9,11 +9,8 @@ terms of the MIT license. A copy of the license can be found in the file
 #error "this file should be included from 'alloc.c' (so aliases can work)"
 #endif
 
-#if defined(MI_MALLOC_OVERRIDE) && defined(_WIN32) && !(defined(MI_SHARED_LIB) && defined(_DLL))
-#error "It is only possible to override "malloc" on Windows when building as a DLL (and linking the C runtime as a DLL)"
-#endif
 
-#if defined(MI_MALLOC_OVERRIDE) && !(defined(_WIN32))
+#if defined(MI_MALLOC_OVERRIDE) && !defined(_DLL)
 
 #if defined(__APPLE__)
 #include <AvailabilityMacros.h>
@@ -127,8 +124,197 @@ typedef void* mi_nothrow_t;
   };
 
 #elif defined(_MSC_VER)
-  // cannot override malloc unless using a dll.
-  // we just override new/delete which does work in a static library.
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR
+  void* __cdecl _expand(
+      _Pre_notnull_           void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW size_t _Size
+      )
+  {
+      return mi_expand(_Block, _Size);
+  }
+  _Check_return_
+  _ACRTIMP
+  size_t __cdecl _msize_base(
+      _Pre_notnull_ void* _Block
+      ) _CRT_NOEXCEPT
+  {
+      return mi_malloc_size(_Block);
+  }
+  _Check_return_
+  _ACRTIMP _CRT_HYBRIDPATCHABLE
+  size_t __cdecl _msize(
+      _Pre_notnull_ void* _Block
+      )
+  {
+      return mi_malloc_size(_Block);
+  }
+  _ACRTIMP
+  void __cdecl _free_base(
+      _Pre_maybenull_ _Post_invalid_ void* _Block
+      )
+  {
+      mi_free(_Block);
+  }
+  _ACRTIMP _CRT_HYBRIDPATCHABLE
+  void __cdecl free(
+      _Pre_maybenull_ _Post_invalid_ void* _Block
+      )
+  {
+      mi_free(_Block);
+  }
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRT_JIT_INTRINSIC _CRTRESTRICT _CRT_HYBRIDPATCHABLE
+  void* __cdecl malloc(
+      _In_ _CRT_GUARDOVERFLOW size_t _Size
+      )
+  {
+      return mi_malloc(_Size);
+  }
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _malloc_base(
+      _In_ size_t _Size
+      )
+  {
+      return mi_malloc(_Size);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _realloc_base(
+      _Pre_maybenull_ _Post_invalid_  void*  _Block,
+      _In_                            size_t _Size
+      )
+  {
+      return mi_realloc(_Block, _Size);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT _CRT_HYBRIDPATCHABLE
+  void* __cdecl realloc(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Size
+      )
+  {
+      return mi_realloc(_Block, _Size);
+  }
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Count * _Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _calloc_base(
+      _In_ size_t _Count,
+      _In_ size_t _Size
+      )
+  {
+      return mi_calloc(_Count, _Size);
+  }
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Count * _Size)
+  _ACRTIMP _CRT_JIT_INTRINSIC _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl calloc(
+      _In_ _CRT_GUARDOVERFLOW size_t _Count,
+      _In_ _CRT_GUARDOVERFLOW size_t _Size
+      )
+  {
+      return mi_calloc(_Count, _Size);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Count * _Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _recalloc_base(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_                           size_t _Count,
+      _In_                           size_t _Size
+      )
+  {
+      return mi_recalloc(_Block, _Count, _Size);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Count * _Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _recalloc(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Count,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Size
+      )
+  {
+      return mi_recalloc(_Block, _Count, _Size);
+  }
+  _ACRTIMP
+  void __cdecl _aligned_free(
+      _Pre_maybenull_ _Post_invalid_ void* _Block
+      )
+  {
+      mi_free(_Block);
+  }
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _aligned_malloc(
+      _In_ _CRT_GUARDOVERFLOW size_t _Size,
+      _In_                    size_t _Alignment
+      )
+  {
+      return mi_malloc_aligned(_Size, _Alignment);
+  }
+  _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _aligned_offset_malloc(
+      _In_ _CRT_GUARDOVERFLOW size_t _Size,
+      _In_                    size_t _Alignment,
+      _In_                    size_t _Offset
+      )
+  {
+      return mi_malloc_aligned_at(_Size, _Alignment, _Offset);
+  }
+  _Check_return_
+  _ACRTIMP
+  size_t __cdecl _aligned_msize(
+      _Pre_notnull_ void*  _Block,
+      _In_          size_t _Alignment,
+      _In_          size_t _Offset
+      )
+  {
+      return mi_malloc_size(_Block);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _aligned_offset_realloc(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Size,
+      _In_                           size_t _Alignment,
+      _In_                           size_t _Offset
+      )
+  {
+      return mi_realloc_aligned_at(_Block, _Size, _Alignment, _Offset);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Count * _Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _aligned_offset_recalloc(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Count,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Size,
+      _In_                           size_t _Alignment,
+      _In_                           size_t _Offset
+      )
+  {
+      return mi_recalloc_aligned_at(_Block, _Count, _Size, _Alignment, _Offset);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _aligned_realloc(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Size,
+      _In_                           size_t _Alignment
+      )
+  {
+      return mi_realloc_aligned(_Block, _Size, _Alignment);
+  }
+  _Success_(return != 0) _Check_return_ _Ret_maybenull_ _Post_writable_byte_size_(_Count * _Size)
+  _ACRTIMP _CRTALLOCATOR _CRTRESTRICT
+  void* __cdecl _aligned_recalloc(
+      _Pre_maybenull_ _Post_invalid_ void*  _Block,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Count,
+      _In_ _CRT_GUARDOVERFLOW        size_t _Size,
+      _In_                           size_t _Alignment
+      )
+  {
+      return mi_recalloc_aligned(_Block, _Count, _Size, _Alignment);
+  }
 #else
   // On all other systems forward allocation primitives to our API
   mi_decl_export void* malloc(size_t size)              MI_FORWARD1(mi_malloc, size)
@@ -276,7 +462,9 @@ extern "C" {
 void  cfree(void* p)                                    { mi_free(p); }
 void* pvalloc(size_t size)                              { return mi_pvalloc(size); }
 void* memalign(size_t alignment, size_t size)           { return mi_memalign(alignment, size); }
+#if !defined(_WIN32)
 void* _aligned_malloc(size_t alignment, size_t size)    { return mi_aligned_alloc(alignment, size); }
+#endif
 void* reallocarray(void* p, size_t count, size_t size)  { return mi_reallocarray(p, count, size); }
 // some systems define reallocarr so mark it as a weak symbol (#751)
 mi_decl_weak int reallocarr(void* p, size_t count, size_t size)    { return mi_reallocarr(p, count, size); }
@@ -311,4 +499,4 @@ mi_decl_weak int reallocarr(void* p, size_t count, size_t size)    { return mi_r
 #pragma GCC visibility pop
 #endif
 
-#endif // MI_MALLOC_OVERRIDE && !_WIN32
+#endif // MI_MALLOC_OVERRIDE
diff --git a/test/main-override.c b/test/main-override.c
index 284fdd20..9a97fd41 100644
--- a/test/main-override.c
+++ b/test/main-override.c
@@ -8,7 +8,16 @@
 int main() {
   mi_version();       // ensure mimalloc library is linked
   void* p1 = malloc(78);
+  if (!mi_is_in_heap_region(p1)) {
+     printf("p1: malloc failed to allocate in heap region\n");
+     return 1;
+  }
+ 
   void* p2 = malloc(24);
+  if (!mi_is_in_heap_region(p2)) {
+     printf("p2: malloc failed to allocate in heap region\n");
+     return 1;
+  }
   free(p1);
   p1 = malloc(8);
   //char* s = strdup("hello\n");