diff --git a/src/bits.h b/src/bits.h
index e80b7973..8776ecec 100644
--- a/src/bits.h
+++ b/src/bits.h
@@ -345,11 +345,16 @@ typedef struct MDBX_page {
 #define MIN_PAGESIZE 512u
 
 #define MIN_MAPSIZE (MIN_PAGESIZE * MIN_PAGENO)
-#define MAX_MAPSIZE                                                            \
-  ((sizeof(size_t) < 8)                                                        \
-       ? UINT32_C(0x7ff80000)                                                  \
-       : ((sizeof(pgno_t) > 4) ? UINT64_C(0x7fffFFFFfff80000)                  \
-                               : MAX_PAGENO * (uint64_t)MAX_PAGESIZE))
+#if defined(_WIN32) || defined(_WIN64)
+#define MAX_MAPSIZE32 UINT32_C(0x38000000)
+#else
+#define MAX_MAPSIZE32 UINT32_C(0x7ff80000)
+#endif
+#define MAX_MAPSIZE64                                                          \
+  ((sizeof(pgno_t) > 4) ? UINT64_C(0x7fffFFFFfff80000)                         \
+                        : MAX_PAGENO * (uint64_t)MAX_PAGESIZE)
+
+#define MAX_MAPSIZE ((sizeof(size_t) < 8) ? MAX_MAPSIZE32 : MAX_MAPSIZE64)
 
 #pragma pack(pop)