diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 4b34be7d..2987e754 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -22,6 +22,7 @@
 * API projects don't include the `google-common-protos` dependency by default.
 * API projects updated the `grpcio` dependency to `1.66.1`.
 * API projects updated the `frequenz-api-common` dependency to `0.6`.
+* Added a new default option `asyncio_default_fixture_loop_scope = "function"` for `pytest-asyncio` as not providing a value is deprecated.
 
 ## Bug Fixes
 
diff --git a/cookiecutter/{{cookiecutter.github_repo_name}}/pyproject.toml b/cookiecutter/{{cookiecutter.github_repo_name}}/pyproject.toml
index e1e323e7..7ec6bbec 100644
--- a/cookiecutter/{{cookiecutter.github_repo_name}}/pyproject.toml
+++ b/cookiecutter/{{cookiecutter.github_repo_name}}/pyproject.toml
@@ -197,6 +197,7 @@ disable = [
 {%- if cookiecutter.type != "api" %}
 testpaths = ["tests", "src"]
 asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 required_plugins = ["pytest-asyncio", "pytest-mock"]
 {%- else %}
 testpaths = ["pytests"]
diff --git a/pyproject.toml b/pyproject.toml
index 694e17e7..7dd3d44a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -196,6 +196,8 @@ ignore_missing_imports = true
 
 [tool.pytest.ini_options]
 testpaths = ["src", "tests"]
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 markers = [
   "integration: integration tests (deselect with '-m \"not integration\"')",
   "cookiecutter: integration tests (deselect with '-m \"not cookiecutter\"')",
diff --git a/tests_golden/integration/test_cookiecutter_generation/actor/frequenz-actor-test/pyproject.toml b/tests_golden/integration/test_cookiecutter_generation/actor/frequenz-actor-test/pyproject.toml
index 9ab6808c..3640aa21 100644
--- a/tests_golden/integration/test_cookiecutter_generation/actor/frequenz-actor-test/pyproject.toml
+++ b/tests_golden/integration/test_cookiecutter_generation/actor/frequenz-actor-test/pyproject.toml
@@ -155,6 +155,7 @@ disable = [
 [tool.pytest.ini_options]
 testpaths = ["tests", "src"]
 asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 required_plugins = ["pytest-asyncio", "pytest-mock"]
 
 [tool.mypy]
diff --git a/tests_golden/integration/test_cookiecutter_generation/app/frequenz-app-test/pyproject.toml b/tests_golden/integration/test_cookiecutter_generation/app/frequenz-app-test/pyproject.toml
index a24de52d..9ee5132e 100644
--- a/tests_golden/integration/test_cookiecutter_generation/app/frequenz-app-test/pyproject.toml
+++ b/tests_golden/integration/test_cookiecutter_generation/app/frequenz-app-test/pyproject.toml
@@ -154,6 +154,7 @@ disable = [
 [tool.pytest.ini_options]
 testpaths = ["tests", "src"]
 asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 required_plugins = ["pytest-asyncio", "pytest-mock"]
 
 [tool.mypy]
diff --git a/tests_golden/integration/test_cookiecutter_generation/lib/frequenz-test-python/pyproject.toml b/tests_golden/integration/test_cookiecutter_generation/lib/frequenz-test-python/pyproject.toml
index 44e8ac01..5007e812 100644
--- a/tests_golden/integration/test_cookiecutter_generation/lib/frequenz-test-python/pyproject.toml
+++ b/tests_golden/integration/test_cookiecutter_generation/lib/frequenz-test-python/pyproject.toml
@@ -151,6 +151,7 @@ disable = [
 [tool.pytest.ini_options]
 testpaths = ["tests", "src"]
 asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 required_plugins = ["pytest-asyncio", "pytest-mock"]
 
 [tool.mypy]
diff --git a/tests_golden/integration/test_cookiecutter_generation/model/frequenz-model-test/pyproject.toml b/tests_golden/integration/test_cookiecutter_generation/model/frequenz-model-test/pyproject.toml
index 439989d3..74c61e84 100644
--- a/tests_golden/integration/test_cookiecutter_generation/model/frequenz-model-test/pyproject.toml
+++ b/tests_golden/integration/test_cookiecutter_generation/model/frequenz-model-test/pyproject.toml
@@ -155,6 +155,7 @@ disable = [
 [tool.pytest.ini_options]
 testpaths = ["tests", "src"]
 asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 required_plugins = ["pytest-asyncio", "pytest-mock"]
 
 [tool.mypy]