diff --git a/CMake/options.cmake b/CMake/options.cmake
index 2c8b0c48d..affe2a43b 100644
--- a/CMake/options.cmake
+++ b/CMake/options.cmake
@@ -63,6 +63,16 @@ if((NOT APPLE OR OPTION_APPLE_X11) AND NOT WIN32)
    endif(X11_FOUND)
 endif((NOT APPLE OR OPTION_APPLE_X11) AND NOT WIN32)
 
+if (OPTION_APPLE_X11)
+  include_directories (AFTER SYSTEM /opt/X11/include/freetype2)
+  if (PATH_TO_XLIBS)
+    set (LDFLAGS "-L${PATH_TO_XLIBS} ${LDFLAGS}")
+  endif (PATH_TO_XLIBS)
+  if (X11_INCLUDE_DIR)
+    list (APPEND FLTK_CFLAGS "-I${X11_INCLUDE_DIR}")
+  endif (X11_INCLUDE_DIR)
+endif (OPTION_APPLE_X11)
+
 #######################################################################
 option(OPTION_USE_POLL "use poll if available" OFF)
 mark_as_advanced(OPTION_USE_POLL)
diff --git a/CMake/setup.cmake b/CMake/setup.cmake
index 4d960a537..c6b5d7f05 100644
--- a/CMake/setup.cmake
+++ b/CMake/setup.cmake
@@ -99,9 +99,11 @@ if(APPLE)
    set(HAVE_SCANDIR 1)
    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-deprecated")
    if(OPTION_APPLE_X11)
-     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -U__APPLE__ -mmacosx-version-min=10.3")
+     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -U__APPLE__")
      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -U__APPLE__")
-     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -L/opt/X11/lib -lfontconfig")
+     if(${CMAKE_SYSTEM_VERSION} VERSION_GREATER 16.9.0)
+       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  -D_LIBCPP_HAS_THREAD_API_PTHREAD")
+     endif(${CMAKE_SYSTEM_VERSION} VERSION_GREATER 16.9.0)
    else()
      set(__APPLE_QUARTZ__ 1)
      set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -framework Cocoa")