diff --git a/include/cmath b/include/cmath
index be3c3ee76..1b5225c04 100644
--- a/include/cmath
+++ b/include/cmath
@@ -398,7 +398,7 @@ using ::cbrtf;
 using ::copysign;
 using ::copysignf;
 
-#ifndef _LIBCPP_MSVCRT
+#if !defined(_LIBCPP_MSVCRT) || ((_VC_CRT_NAJOR_VERSION-0) >= 14)
 using ::erf;
 using ::erff;
 using ::erfc;
diff --git a/include/math.h b/include/math.h
index ef4e9678d..18dd3cc49 100644
--- a/include/math.h
+++ b/include/math.h
@@ -293,6 +293,9 @@ long double    truncl(long double x);
 */
 
 #include <__config>
+#if defined(_LIBCPP_MSVCRT)
+#include <crtversion.h>
+#endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header