diff --git a/py/mpz.c b/py/mpz.c
index b5cc7d1838..fc1109fdd7 100644
--- a/py/mpz.c
+++ b/py/mpz.c
@@ -37,9 +37,9 @@
 #if MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_MPZ
 
 #define DIG_SIZE (MPZ_DIG_SIZE)
-#define DIG_MASK ((1L << DIG_SIZE) - 1)
-#define DIG_MSB  (1L << (DIG_SIZE - 1))
-#define DIG_BASE (1L << DIG_SIZE)
+#define DIG_MASK ((MPZ_LONG_1 << DIG_SIZE) - 1)
+#define DIG_MSB  (MPZ_LONG_1 << (DIG_SIZE - 1))
+#define DIG_BASE (MPZ_LONG_1 << DIG_SIZE)
 
 /*
  mpz is an arbitrary precision integer type with a public API.
diff --git a/py/mpz.h b/py/mpz.h
index 9dbbbc373a..35e06c5658 100644
--- a/py/mpz.h
+++ b/py/mpz.h
@@ -36,7 +36,7 @@
 // depending on the machine, but it (and MPZ_DIG_SIZE) can be freely changed so
 // long as the constraints mentioned above are met.
 
-#if defined(__x86_64__)
+#if defined(__x86_64__) || defined(_WIN64)
 // 64-bit machine, using 32-bit storage for digits
 typedef uint32_t mpz_dig_t;
 typedef uint64_t mpz_dbl_dig_t;
@@ -50,6 +50,12 @@ typedef int32_t mpz_dbl_dig_signed_t;
 #define MPZ_DIG_SIZE (16)
 #endif
 
+#ifdef _WIN64
+  #define MPZ_LONG_1 1i64
+#else
+  #define MPZ_LONG_1 1L
+#endif
+
 #define MPZ_NUM_DIG_FOR_INT (sizeof(mp_int_t) * 8 / MPZ_DIG_SIZE + 1)
 #define MPZ_NUM_DIG_FOR_LL (sizeof(long long) * 8 / MPZ_DIG_SIZE + 1)
 
diff --git a/py/objint_mpz.c b/py/objint_mpz.c
index b75cc8c0bc..7eff54c53c 100644
--- a/py/objint_mpz.c
+++ b/py/objint_mpz.c
@@ -45,7 +45,7 @@
 
 #if MICROPY_PY_SYS_MAXSIZE
 // Export value for sys.maxsize
-#define DIG_MASK ((1L << MPZ_DIG_SIZE) - 1)
+#define DIG_MASK ((MPZ_LONG_1 << MPZ_DIG_SIZE) - 1)
 STATIC const mpz_dig_t maxsize_dig[MPZ_NUM_DIG_FOR_INT] = {
     (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 0) & DIG_MASK,
     #if (MP_SSIZE_MAX >> MPZ_DIG_SIZE * 0) > DIG_MASK