diff --git a/.github/workflows/check_docs.yml b/.github/workflows/check_docs.yml
index 70bf6de0..99aecda1 100644
--- a/.github/workflows/check_docs.yml
+++ b/.github/workflows/check_docs.yml
@@ -32,7 +32,7 @@ jobs:
           path: .venv
           key: nitypes-with-docs-${{ runner.os }}-py${{ steps.setup-python.outputs.python-version }}-${{ hashFiles('poetry.lock') }}
       - name: Install nitypes (with docs)
-        run: poetry install -v --with docs
+        run: poetry install -v --only main,docs
       - name: Generate docs
         run:  poetry run sphinx-build docs docs/_build -b html -W --keep-going
       - name: Upload docs artifact
diff --git a/docs/conf.py b/docs/conf.py
index abcf0d7f..665dc4a5 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -74,6 +74,7 @@ def setup(sphinx):
 
 
 intersphinx_mapping = {
+    "numpy": ("https://numpy.org/doc/stable/", None),
     "python": ("https://docs.python.org/3", None),
 }