diff --git a/include/bx/os.h b/include/bx/os.h
index 2c94b62..3785c66 100644
--- a/include/bx/os.h
+++ b/include/bx/os.h
@@ -12,19 +12,22 @@
 #	include <windows.h>
 #elif BX_PLATFORM_NACL || BX_PLATFORM_ANDROID || BX_PLATFORM_LINUX || BX_PLATFORM_OSX || BX_PLATFORM_IOS
 #	include <sched.h> // sched_yield
-#	if BX_PLATFORM_OSX || BX_PLATFORM_NACL
+#	if BX_PLATFORM_IOS || BX_PLATFORM_OSX || BX_PLATFORM_NACL
 #		include <pthread.h> // mach_port_t
-#	endif // BX_PLATFORM_OSX || BX_PLATFORM_NACL
+#	endif // BX_PLATFORM_IOS || BX_PLATFORM_OSX || BX_PLATFORM_NACL
+
 #	if BX_PLATFORM_NACL
 #		include <sys/nacl_syscalls.h> // nanosleep
 #	else
 #		include <time.h> // nanosleep
 #		include <dlfcn.h> // dlopen, dlclose, dlsym
 #	endif // BX_PLATFORM_NACL
+
 #	if BX_PLATFORM_LINUX
 #		include <unistd.h> // syscall
 #		include <sys/syscall.h>
 #	endif // BX_PLATFORM_LINUX
+
 #	if BX_PLATFORM_ANDROID
 #		include "debug.h" // getTid is not implemented...
 #	endif // BX_PLATFORM_ANDROID