diff --git a/build/cmake/init.cmake b/build/cmake/init.cmake
index 4dc76635f0..53615a14f3 100644
--- a/build/cmake/init.cmake
+++ b/build/cmake/init.cmake
@@ -468,6 +468,7 @@ if(wxUSE_GUI)
     if(wxUSE_OPENGL)
         if(WXOSX_IPHONE)
             set(OPENGL_FOUND TRUE)
+            set(OPENGL_INCLUDE_DIR "")
             set(OPENGL_LIBRARIES "-framework OpenGLES" "-framework QuartzCore" "-framework GLKit")
         else()
             find_package(OpenGL)