diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7571f0e..b7b71cf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,7 +27,6 @@ jobs:
     - name: Install and build
       run: |
         python -m pip install -r requirements-dev.txt
-        python -m pip install -r requirements.txt
         python -m pip install .
 
     - name: Run tests
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 1e9dbfb..333b4f3 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -36,11 +36,15 @@ mypy-extensions==1.0.0
     # via black
 nodeenv==1.8.0
     # via pre-commit
+numpy==1.26.2
+    # via pandas
 packaging==23.2
     # via
     #   black
     #   build
     #   pytest
+pandas==2.1.3
+    # via wsimod (pyproject.toml)
 pathspec==0.11.2
     # via black
 pip-tools==7.3.0
@@ -61,14 +65,22 @@ pytest==7.4.3
     #   wsimod (pyproject.toml)
 pytest-cov==4.1.0
     # via wsimod (pyproject.toml)
+python-dateutil==2.8.2
+    # via pandas
+pytz==2023.3.post1
+    # via pandas
 pyyaml==6.0.1
     # via
     #   pre-commit
     #   wsimod (pyproject.toml)
 ruff==0.1.4
     # via wsimod (pyproject.toml)
+six==1.16.0
+    # via python-dateutil
 tqdm==4.66.1
     # via wsimod (pyproject.toml)
+tzdata==2023.3
+    # via pandas
 virtualenv==20.24.6
     # via pre-commit
 wheel==0.41.3