diff --git a/libco.h b/libco.h
index 792df0bd..0ea47789 100644
--- a/libco.h
+++ b/libco.h
@@ -1,5 +1,5 @@
 /*
-  libco v18 (2016-09-14)
+  libco v18.01 (2017-01-22)
   author: byuu
   license: public domain
 */
diff --git a/settings.h b/settings.h
index b419683a..d8037bc4 100644
--- a/settings.h
+++ b/settings.h
@@ -1,4 +1,4 @@
-#ifdef LIBCO_C
+#if defined(LIBCO_C)
 
 /*[amd64, arm, ppc, x86]:
    by default, co_swap_function is marked as a text (code) section
@@ -10,8 +10,8 @@
    do not use this unless you are certain your application won't use SSE */
 /* #define LIBCO_NO_SSE */
 
-#ifdef LIBCO_C
-  #ifdef LIBCO_MP
+#if defined(LIBCO_C)
+  #if defined(LIBCO_MP)
     #define thread_local __thread
   #else
     #define thread_local
@@ -19,18 +19,20 @@
 #endif
 
 #if __STDC_VERSION__ >= 201112L
-  #ifndef _MSC_VER
+  #if !defined(_MSC_VER)
     #include <stdalign.h>
   #endif
 #else
   #define alignas(bytes)
 #endif
 
-#ifndef _MSC_VER
-  #define section(name) __attribute__((section("." #name "#")))
-#else
+#if defined(_MSC_VER)
   #define section(name) __declspec(allocate("." #name))
+#elif defined(__APPLE__)
+  #define section(name) __attribute__((section("__TEXT,__" #name)))
+#else
+  #define section(name) __attribute__((section("." #name "#")))
 #endif
 
-/* ifdef LIBCO_C */
+/* if defined(LIBCO_C) */
 #endif