diff --git a/atdna/CMakeLists.txt b/atdna/CMakeLists.txt
index ac53c7a..b60adb9 100644
--- a/atdna/CMakeLists.txt
+++ b/atdna/CMakeLists.txt
@@ -167,7 +167,7 @@ macro(atdna out)
 
   # OSX Extra
   elseif(APPLE)
-    list(APPEND extraargs -isysroot ${CMAKE_OSX_SYSROOT} -isysroot
+    list(APPEND extraargs -isysroot ${CMAKE_OSX_SYSROOT} -I ${CMAKE_OSX_SYSROOT}/usr/include -isysroot
          ${CMAKE_OSX_SYSROOT}/../../../../../Toolchains/XcodeDefault.xctoolchain)
   endif()