diff --git a/Eigen/src/Core/MathFunctions.h b/Eigen/src/Core/MathFunctions.h
index 6d4fc41df..4a21ec975 100644
--- a/Eigen/src/Core/MathFunctions.h
+++ b/Eigen/src/Core/MathFunctions.h
@@ -74,7 +74,6 @@ inline int ei_abs2(int x)  { return x*x; }
 inline int ei_sqrt(int)  { ei_assert(false); return 0; }
 inline int ei_exp(int)  { ei_assert(false); return 0; }
 inline int ei_log(int)  { ei_assert(false); return 0; }
-inline int ei_erf(int)  { ei_assert(false); return 0; }
 inline int ei_sin(int)  { ei_assert(false); return 0; }
 inline int ei_cos(int)  { ei_assert(false); return 0; }
 inline int ei_atan2(int, int) { ei_assert(false); return 0; }
@@ -129,9 +128,6 @@ inline float ei_norm1(float x) { return ei_abs(x); }
 inline float ei_sqrt(float x)  { return std::sqrt(x); }
 inline float ei_exp(float x)   { return std::exp(x); }
 inline float ei_log(float x)   { return std::log(x); }
-#if (!defined(_MSC_VER) && !defined(__CYGWIN__))
-inline float ei_erf(float x)   { return erff(x); }
-#endif
 inline float ei_sin(float x)   { return std::sin(x); }
 inline float ei_cos(float x)   { return std::cos(x); }
 inline float ei_atan2(float y, float x) { return std::atan2(y,x); }
@@ -179,9 +175,6 @@ inline double ei_norm1(double x) { return ei_abs(x); }
 inline double ei_sqrt(double x)  { return std::sqrt(x); }
 inline double ei_exp(double x)   { return std::exp(x); }
 inline double ei_log(double x)   { return std::log(x); }
-#if (!defined(_MSC_VER) && !defined(__CYGWIN__))
-inline double ei_erf(double x)   { return erf(x); }
-#endif
 inline double ei_sin(double x)   { return std::sin(x); }
 inline double ei_cos(double x)   { return std::cos(x); }
 inline double ei_atan2(double y, double x) { return std::atan2(y,x); }
@@ -303,9 +296,6 @@ inline long double ei_abs2(long double x)  { return x*x; }
 inline long double ei_sqrt(long double x)  { return std::sqrt(x); }
 inline long double ei_exp(long double x)   { return std::exp(x); }
 inline long double ei_log(long double x)   { return std::log(x); }
-#if (!defined(_MSC_VER) && !defined(__CYGWIN__))
-inline long double ei_erf(long double x)   { return erfl(x); }
-#endif
 inline long double ei_sin(long double x)   { return std::sin(x); }
 inline long double ei_cos(long double x)   { return std::cos(x); }
 inline long double ei_atan2(long double y, long double x) { return std::atan2(y,x); }