diff --git a/src/osal.h b/src/osal.h
index b690a5a5..be7e44d3 100644
--- a/src/osal.h
+++ b/src/osal.h
@@ -753,12 +753,12 @@ typedef NTSTATUS(NTAPI *MDBX_NtFsControlFile)(
     OUT OPTIONAL PVOID OutputBuffer, IN ULONG OutputBufferLength);
 extern MDBX_NtFsControlFile mdbx_NtFsControlFile;
 
-#ifndef _WIN32_WINNT_WIN8
+#if !defined(_WIN32_WINNT_WIN8) || _WIN32_WINNT < _WIN32_WINNT_WIN8
 typedef struct _WIN32_MEMORY_RANGE_ENTRY {
   PVOID VirtualAddress;
   SIZE_T NumberOfBytes;
 } WIN32_MEMORY_RANGE_ENTRY, *PWIN32_MEMORY_RANGE_ENTRY;
-#endif
+#endif /* Windows 8.x */
 
 typedef BOOL(WINAPI *MDBX_PrefetchVirtualMemory)(
     HANDLE hProcess, ULONG_PTR NumberOfEntries,