diff --git a/setup.py b/setup.py
index b4279c9..c82db35 100755
--- a/setup.py
+++ b/setup.py
@@ -40,9 +40,9 @@ setup(name='qpms',
         version = "0.2.994",
         packages=['qpms'],
         setup_requires=['cython>=0.28',],
-        install_requires=['cython>=0.28','quaternion','spherical_functions','scipy>=0.18.0'],
+        install_requires=['cython>=0.28','quaternion','spherical_functions','scipy>=0.18.0', 'sympy>=1.2'],
         dependency_links=['https://github.com/moble/quaternion/archive/v2.0.tar.gz','https://github.com/moble/spherical_functions/archive/master.zip'],
-        ext_modules=cythonize([qpms_c], include_path=['qpms']),
+        ext_modules=cythonize([qpms_c], include_path=['qpms'], gdb_debug=True),
         cmdclass = {'build_ext': build_ext},
         )