diff --git a/src/osal.c b/src/osal.c
index 3a652466..c6ae5d8f 100644
--- a/src/osal.c
+++ b/src/osal.c
@@ -262,8 +262,9 @@ int mdbx_asprintf(char **strp, const char *fmt, ...) {
 
 #ifndef mdbx_memalign_alloc
 int mdbx_memalign_alloc(size_t alignment, size_t bytes, void **result) {
-#if _MSC_VER
-  *result = _aligned_malloc(bytes, alignment);
+#if defined(_WIN32) || defined(_WIN64)
+  (void)alignment;
+  *result = VirtualAlloc(NULL, bytes, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
   return *result ? MDBX_SUCCESS : MDBX_ENOMEM /* ERROR_OUTOFMEMORY */;
 #elif __GLIBC_PREREQ(2, 16) || __STDC_VERSION__ >= 201112L
   *result = memalign(alignment, bytes);
@@ -279,8 +280,8 @@ int mdbx_memalign_alloc(size_t alignment, size_t bytes, void **result) {
 
 #ifndef mdbx_memalign_free
 void mdbx_memalign_free(void *ptr) {
-#if _MSC_VER
-  _aligned_free(ptr);
+#if defined(_WIN32) || defined(_WIN64)
+  VirtualFree(ptr, 0, MEM_RELEASE);
 #else
   mdbx_free(ptr);
 #endif
diff --git a/src/osal.h b/src/osal.h
index e5c48f7c..8a2abc3b 100644
--- a/src/osal.h
+++ b/src/osal.h
@@ -439,8 +439,12 @@ static __inline int mdbx_get_errno(void) {
   return rc;
 }
 
+#ifndef mdbx_memalign_alloc
 int mdbx_memalign_alloc(size_t alignment, size_t bytes, void **result);
+#endif
+#ifndef mdbx_memalign_free
 void mdbx_memalign_free(void *ptr);
+#endif
 
 int mdbx_condmutex_init(mdbx_condmutex_t *condmutex);
 int mdbx_condmutex_lock(mdbx_condmutex_t *condmutex);