diff --git a/setup.py b/setup.py
index 844821a..a564d2c 100644
--- a/setup.py
+++ b/setup.py
@@ -31,6 +31,6 @@ def read_package_variable(key):
     #author_email='giacomo.acciarini@gmail.com',
     packages=find_packages(),
     install_requires=['numpy','pandas','torch','pyfiglet>=0.8.0','tqdm','termcolor','tables','cartopy', 'scikit-learn'],
-    extras_require={'dev': ['pytest', 'pyatmos', 'coverage', 'pytest-xdist', 'flake8']},
+    extras_require={'dev': ['pytest', 'pyatmos', 'coverage', 'pytest-xdist', 'flake8','sphinx_rtd_theme']},
     classifiers=['License :: OSI Approved :: GNU General Public License v3 (GPLv3)', 'Programming Language :: Python :: 3']
 )