diff --git a/.azure-pipelines.yml b/.azure-pipelines.yml
index 620696c22e..7a3eb78a5e 100644
--- a/.azure-pipelines.yml
+++ b/.azure-pipelines.yml
@@ -67,7 +67,11 @@ jobs:
       image: $(ci_runner_image)
       options: $(container_option)
     steps:
-      - script: make htmldocs
+      - script: |
+          virtualenv -p /usr/bin/python3 /tmp/venvhtml
+          . /tmp/venvhtml/bin/activate
+          pip install -r doc/sphinx/requirements.txt
+          make htmldocs
 
   - job: todo
     displayName: 'Search for TODO within source tree'
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4b0680887b..2cdcd864c8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -122,6 +122,9 @@ htmldocs:
   tags: [ 'all' ]
   stage: testsuites
   script:
+    - virtualenv -p /usr/bin/python3 /tmp/venvhtml
+    - . /tmp/venvhtml/bin/activate
+    - pip install -r doc/sphinx/requirements.txt
     - make htmldocs
 
 # some statistics about the code base