diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index c220511c..a8f54e08 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -3,17 +3,21 @@
 find_package(MathJax)
 if (MATHJAX_PATH) 
  message(STATUS "Detected MathJax at ${MATHJAX_PATH}")
+ option(Sphinx_Math_Generator_MathJax " " ON)
 else()
  message(STATUS "MathJax not found automatically")
  option(Sphinx_Math_Generator_MathJax " " OFF)
- if (Sphinx_Math_Generator_MathJax)
-  set(SPHINX_MATH_GENERATOR "mathjax")
-  set(MATHJAX_PATH "MathJax" CACHE STRING "Path to the MathJax directory") 
- else (Sphinx_Math_Generator_MathJax)
-  set(SPHINX_MATH_GENERATOR "pngmath")
- endif (Sphinx_Math_Generator_MathJax)
+ set(MATHJAX_PATH "MathJax" CACHE STRING "Path to the MathJax directory") 
 endif()
 
+if (Sphinx_Math_Generator_MathJax)
+ set(SPHINX_MATH_GENERATOR "mathjax")
+ message(STATUS "Using MathJax")
+else (Sphinx_Math_Generator_MathJax)
+ set(SPHINX_MATH_GENERATOR "pngmath")
+ message(STATUS "Not using MathJax")
+endif (Sphinx_Math_Generator_MathJax)
+
 # the local extensions....
 file(COPY ../foreignlibs/breathe ../foreignlibs/doxylink ../foreignlibs/mpl ../foreignlibs/autocompile DESTINATION ${CMAKE_CURRENT_BINARY_DIR})