diff --git a/.github/workflows/ci-tests.yml b/.github/workflows/ci-tests.yml
index 76054d6a..7dfb3f1d 100644
--- a/.github/workflows/ci-tests.yml
+++ b/.github/workflows/ci-tests.yml
@@ -140,7 +140,7 @@ jobs:
               working-directory: Nominatim/test/bdd
 
             - name: Install mypy and typechecking info
-              run: pip3 install -U mypy osmium uvicorn types-PyYAML types-jinja2 types-psycopg2 types-psutil types-requests types-ujson typing-extensions
+              run: pip3 install -U mypy osmium uvicorn types-PyYAML types-jinja2 types-psycopg2 types-psutil types-requests types-ujson types-Pygments typing-extensions
               if: matrix.flavour != 'oldstuff'
 
             - name: Python static typechecking
diff --git a/docs/develop/Development-Environment.md b/docs/develop/Development-Environment.md
index 7284e99e..3234b8cb 100644
--- a/docs/develop/Development-Environment.md
+++ b/docs/develop/Development-Environment.md
@@ -65,7 +65,7 @@ sudo apt install php-cgi phpunit php-codesniffer \
 
 pip3 install --user behave mkdocs mkdocstrings pytest pytest-asyncio pylint \
                     mypy types-PyYAML types-jinja2 types-psycopg2 types-psutil \
-                    types-ujson types-requests typing-extensions\
+                    types-ujson types-requests types-Pygments typing-extensions\
                     sanic-testing httpx asgi-lifespan
 ```