diff --git a/dmd/root/port.c b/dmd/root/port.c
index f498885b..fce3c952 100644
--- a/dmd/root/port.c
+++ b/dmd/root/port.c
@@ -377,7 +377,11 @@ PortInitializer::PortInitializer()
 int Port::isNan(double r)
 {
 #if __APPLE__
+#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 1080
+    return __inline_isnand(r);
+#else
     return __inline_isnan(r);
+#endif
 #elif __OpenBSD__ || __MINGW32__ || __HAIKU__
     return isnan(r);
 #else
@@ -389,7 +393,11 @@ int Port::isNan(double r)
 int Port::isNan(longdouble r)
 {
 #if __APPLE__
+#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 1080
+    return __inline_isnanl(r);
+#else
     return __inline_isnan(r);
+#endif
 #elif __OpenBSD__ || __MINGW32__ || __HAIKU__
     return isnan(r);
 #else
diff --git a/dmd2/expression.c b/dmd2/expression.c
index c898cdb9..789fd632 100644
--- a/dmd2/expression.c
+++ b/dmd2/expression.c
@@ -24,21 +24,9 @@
 extern "C" char * __cdecl __locale_decpoint;
 #endif
 
-#if __MINGW32__
-#ifndef isnan
-#define isnan _isnan
-#endif
-#endif
-
-#ifdef __APPLE__
-#ifndef isnan
-int isnan(double);
-#endif
-#endif
-
 #include "rmem.h"
-#if IN_DMD
 #include "port.h"
+#if IN_DMD
 #include "root.h"
 #endif
 
@@ -2416,13 +2404,7 @@ complex_t RealExp::toComplex()
 
 int RealEquals(real_t x1, real_t x2)
 {
-//    return (Port::isNan(x1) && Port::isNan(x2)) ||
-#if __APPLE__
-    return (__inline_isnan(x1) && __inline_isnan(x2)) ||
-#else
-    return // special case nans
-          (isnan(x1) && isnan(x2)) ||
-#endif
+    return (Port::isNan(x1) && Port::isNan(x2)) ||
           // and zero, in order to distinguish +0 from -0
           (x1 == 0 && x2 == 0 && 1./x1 == 1./x2) ||
           // otherwise just compare
diff --git a/dmd2/root/port.c b/dmd2/root/port.c
index 29b0b1e8..0beb250d 100644
--- a/dmd2/root/port.c
+++ b/dmd2/root/port.c
@@ -379,7 +379,11 @@ PortInitializer::PortInitializer()
 int Port::isNan(double r)
 {
 #if __APPLE__
+#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 1080
+    return __inline_isnand(r);
+#else
     return __inline_isnan(r);
+#endif
 #elif defined __HAIKU__ || __OpenBSD__
     return isnan(r);
 #else
@@ -391,7 +395,11 @@ int Port::isNan(double r)
 int Port::isNan(longdouble r)
 {
 #if __APPLE__
+#if __MAC_OS_X_VERSION_MAX_ALLOWED >= 1080
+    return __inline_isnanl(r);
+#else
     return __inline_isnan(r);
+#endif
 #elif defined __HAIKU__ || __OpenBSD__
     return isnan(r);
 #else