diff --git a/cython/CMakeLists.txt b/cython/CMakeLists.txt
index 442f8c7..1f5aebe 100644
--- a/cython/CMakeLists.txt
+++ b/cython/CMakeLists.txt
@@ -1,179 +1,193 @@
 # ======================= #
 #                         #
 #   Python specmicp lib   #
 #                         #
 # ======================= #
 
 # Build the cython interface
 # ==========================
 
 find_package(PythonLibs REQUIRED)
 
 include_directories(${PYTHON_INCLUDE_PATH})
 
+option(PYTHON_VERSION_3 "Version of python for cython compilation" ON)
+
 # main variables
 # ===============
 
 # directories
 # -----------
 set(PY_SPECMICP_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/specmicp)
 set(PY_SPECMICP_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR}/specmicp)
 set(PY_INCLUDES_DIR ${CMAKE_CURRENT_SOURCE_DIR}/includes)
 
 # cython flags
 # ------------
-set(CYTHON_FLAGS -3 --cplus -Wextra -I ${PY_INCLUDES_DIR})
+
+set(CYTHON_FLAGS --cplus)
+
+if(${PYTHON_VERSION_3})
+    set(CYTHON_FLAGS ${CYTHON_FLAGS} -3)
+else()
+    set(CYTHON_FLAGS ${CYTHON_FLAGS} -2)
+endif()
+
+if (CMAKE_BUILD_TYPE MATCHES DEBUG)
+    set(CYTHON_FLAGS ${CYTHON_FLAGS} -Wextra)
+endif()
+
 
 # cython compilation macro
 # ------------------------
 # USAGE : cython_compilation(dir base_name dependancies)
 macro(cython_compilation dir base_name)
 add_custom_command(
     OUTPUT ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${base_name}.cpp
-    COMMAND cython ${CYTHON_FLAGS} -I ${dir} -o ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${base_name}.cpp ${dir}/${base_name}.pyx
+    COMMAND cython ${CYTHON_FLAGS} -I ${dir} -I ${PY_INCLUDES_DIR} -o ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${base_name}.cpp ${dir}/${base_name}.pyx
     DEPENDS ${ARGN})
 # ${ARGN} is the list of arguments passed after the last expected argument
 # i.e. ${ARGN} = dependancies
 endmacro(cython_compilation)
 
 # common includes
 # ===============
 
 add_custom_target(cython_includes SOURCES
     ${PY_INCLUDES_DIR}/memory.pxd
     ${PY_INCLUDES_DIR}/eigen.pxd
 )
 
 # specmicp module
 # ===============
 
 file(COPY ${PY_SPECMICP_SOURCE_DIR}/__init__.py
      DESTINATION ${PY_SPECMICP_BINARY_DIR}
 )
 
 # specmicp.database
 # =================
 
 # Sources
 add_custom_target(cython_specmicp_database_files SOURCES
     ${PY_SPECMICP_SOURCE_DIR}/database.pxd
     ${PY_SPECMICP_SOURCE_DIR}/database.pyx
 )
 set(cython_database_dependancies
         ${PY_SPECMICP_SOURCE_DIR}/database.pxd
         ${PY_SPECMICP_SOURCE_DIR}/database.pyx
         ${PY_INCLUDES_DIR}/memory.pxd
         ${PY_INCLUDES_DIR}/eigen.pxd
 )
 
 # Cython compilation
 cython_compilation(${PY_SPECMICP_SOURCE_DIR} database ${cython_database_dependancies})
 
 # build the specmicp.database library
 add_library(database SHARED ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/database.cpp ${DATABASE_LIBFILE})
 
 set_target_properties(database
     PROPERTIES PREFIX ""
     LIBRARY_OUTPUT_DIRECTORY "${PY_SPECMICP_BINARY_DIR}"
 )
 #target_link_libraries(database specmicp_database)
 
 # specmicp.equilibrium_state
 # ==========================
 
 # Sources
 add_custom_target(cython_specmicp_equilibrium_state_files SOURCES
     ${PY_SPECMICP_SOURCE_DIR}/equilibrium_state.pxd
     ${PY_SPECMICP_SOURCE_DIR}/equilibrium_state.pyx
 )
 set(cython_equilibrium_state_dependancies
         ${PY_SPECMICP_SOURCE_DIR}/equilibrium_state.pxd
         ${PY_SPECMICP_SOURCE_DIR}/equilibrium_state.pyx
         ${PY_INCLUDES_DIR}/eigen.pxd
 )
 # Cython compilation
 cython_compilation(${PY_SPECMICP_SOURCE_DIR} equilibrium_state ${cython_equilibrium_state_dependancies})
 
 add_library(equilibrium_state SHARED
     ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/equilibrium_state.cpp
     ${SPECMICP_LIBFILE}
     ${DATABASE_LIBFILE})
 
 set_target_properties(equilibrium_state
     PROPERTIES PREFIX ""
     LIBRARY_OUTPUT_DIRECTORY "${PY_SPECMICP_BINARY_DIR}"
 )
 target_link_libraries(equilibrium_state jsoncpp)
 
 
 # specmic.reaction_path
 # =====================
 
 # Sources
 add_custom_target(cython_specmicp_reaction_path_files SOURCES
     ${PY_SPECMICP_SOURCE_DIR}/solver_options.pxd
     ${PY_SPECMICP_SOURCE_DIR}/reaction_path.pxd
     ${PY_SPECMICP_SOURCE_DIR}/reaction_path.pyx
 )
 set(cython_reaction_path_dependancies
         ${PY_SPECMICP_SOURCE_DIR}/solver_options.pxd
         ${PY_SPECMICP_SOURCE_DIR}/equilibrium_state.pxd
         ${PY_SPECMICP_SOURCE_DIR}/equilibrium_state.pyx
         ${PY_SPECMICP_SOURCE_DIR}/reaction_path.pxd
         ${PY_SPECMICP_SOURCE_DIR}/reaction_path.pyx
         ${PY_INCLUDES_DIR}/eigen.pxd
 )
 # Cython compilation
 cython_compilation(${PY_SPECMICP_SOURCE_DIR} reaction_path ${cython_reaction_path_dependancies})
 
 # build the specmicp.reaction_path library
 add_library(reaction_path SHARED
     ${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/reaction_path.cpp
     ${SPECMICP_LIBFILE}
     ${DATABASE_LIBFILE})
 
 set_target_properties(reaction_path
     PROPERTIES PREFIX ""
     LIBRARY_OUTPUT_DIRECTORY "${PY_SPECMICP_BINARY_DIR}"
 )
 target_link_libraries(reaction_path jsoncpp)
 
 
 
 # ========== #
 #            #
 #    TEST    #
 #            #
 # ========== #
 
 # Prelude
 # =======
 
 # directories
 # -----------
 set(TEST_DIR ${CMAKE_CURRENT_SOURCE_DIR}/../tests/cython)
 set(BINARY_TEST_DIR ${CMAKE_CURRENT_BINARY_DIR}/tests)
 
 # variables to configure the scripts
 # ----------------------------------
 set(python_module_path ${CMAKE_CURRENT_BINARY_DIR})
 set(database_path ${CMAKE_CURRENT_BINARY_DIR}/../data/cemdata_specmicp.js)
 
 # macro to configure the scripts
 # -------------------------------
 macro(configure_python_test test_name)
 configure_file(${TEST_DIR}/${test_name} ${BINARY_TEST_DIR}${CMAKE_FILES_DIRECTORY}/${test_name} @ONLY)
 file(COPY ${BINARY_TEST_DIR}${CMAKE_FILES_DIRECTORY}/${test_name}
   DESTINATION ${BINARY_TEST_DIR}
   FILE_PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ
   GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
 endmacro(configure_python_test)
 
 # Scripts
 # =======
 
 # database unittest
 configure_python_test(database.py)
 # thermocarbo
 configure_python_test(thermocarbo.py)