diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index c82051b..96cd0fd 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -27,7 +27,7 @@ jobs:
       - name: Pre-commit
         uses: pre-commit/action@v3.0.1
       - name: Tests
-        run: pytest --cov=onvif --cov-report=term-missing --cov-report=xml tests
+        run: python -m pytest --cov=onvif --cov-report=term-missing --cov-report=xml tests
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v5.0.2
         with:
diff --git a/requirements.txt b/requirements.txt
index 5a96384..8fd3a20 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
 # Package
+ciso8601==2.1.3
 httpx==0.28.0
 zeep[async]==4.3.1