diff --git a/.github/workflows/build_docs.yml b/.github/workflows/build_docs.yml
index 52e67b4..47ac15f 100644
--- a/.github/workflows/build_docs.yml
+++ b/.github/workflows/build_docs.yml
@@ -32,7 +32,7 @@ jobs:
           channels: conda-forge
 
       - name: Prepare
-        run: conda install doxygen sphinx breathe pybind11 sphinx_rtd_theme furo nlohmann_json zeromq fmt
+        run: conda install doxygen sphinx=7.1.2 breathe pybind11 sphinx_rtd_theme furo nlohmann_json zeromq fmt
 
       - name: Build library 
         run: |