diff --git a/tommath_private.h b/tommath_private.h
index be620dbc..74503e65 100644
--- a/tommath_private.h
+++ b/tommath_private.h
@@ -178,7 +178,7 @@ MP_STATIC_ASSERT(min_prec_geq_uint64size,
 #if defined(__STDC_IEC_559__) || defined(__GCC_IEC_559) \
    || defined(__x86_64__) || defined(_M_X64) || defined(_M_AMD64) \
    || defined(__i386__) || defined(_M_X86) || defined(_M_IX86) \
-   || defined(__aarch64__) || defined(__arm__)
+   || defined(__aarch64__) || defined(__arm__) || defined(_M_ARM64)
 #define MP_HAS_SET_DOUBLE
 #endif