diff --git a/setup.py b/setup.py
index b02417c..65f8d94 100644
--- a/setup.py
+++ b/setup.py
@@ -19,11 +19,11 @@
     readme = f.read()
 
 extra_reqs = {'tests': ['pytest'],
-              'docs': ['sphinx',
+              'docs': ['sphinx==7.4.7',
                        'dask',
-                       'sphinx_rtd_theme',
-                       'matplotlib',
-                       'sphinx-gallery']}
+                       'sphinx_rtd_theme==2.0.0',
+                       'matplotlib==3.9.1',
+                       'sphinx-gallery==0.17.0']}
 
 setup(name='nrt',
       version=version,