diff --git a/.github/workflows/build_docs.yml b/.github/workflows/build_docs.yml
index 563103b..e512c8e 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 conda-build conda-verify pytest anaconda-client sphinx breathe sphinx_rtd_theme zeromq
+        run: conda install conda-build conda-verify pytest anaconda-client sphinx breathe sphinx_rtd_theme nlohmann_json zeromq
 
       - name: Build library 
         run: mkdir build && cd build && cmake .. -DAARE_SYSTEM_LIBRARIES=ON -DAARE_DOCS=ON && make -j 2