diff --git a/.copier-answers.yml b/.copier-answers.yml
index 12fe3e1..a2b4d3a 100644
--- a/.copier-answers.yml
+++ b/.copier-answers.yml
@@ -1,5 +1,5 @@
 # Changes here will be overwritten by Copier
-_commit: 2.1.0-33-g516ffaa
+_commit: 2.1.0-36-g445567b
 _src_path: gh:DiamondLightSource/python-copier-template
 author_email: tom.cobb@diamond.ac.uk
 author_name: Tom Cobb
diff --git a/pyproject.toml b/pyproject.toml
index 725a1e8..2853f11 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -98,11 +98,18 @@ commands =
 src = ["src", "tests"]
 line-length = 88
 lint.select = [
-    "B",  # flake8-bugbear - https://docs.astral.sh/ruff/rules/#flake8-bugbear-b
-    "C4", # flake8-comprehensions - https://docs.astral.sh/ruff/rules/#flake8-comprehensions-c4
-    "E",  # pycodestyle errors - https://docs.astral.sh/ruff/rules/#error-e
-    "F",  # pyflakes rules - https://docs.astral.sh/ruff/rules/#pyflakes-f
-    "W",  # pycodestyle warnings - https://docs.astral.sh/ruff/rules/#warning-w
-    "I",  # isort - https://docs.astral.sh/ruff/rules/#isort-i
-    "UP", # pyupgrade - https://docs.astral.sh/ruff/rules/#pyupgrade-up
+    "B",   # flake8-bugbear - https://docs.astral.sh/ruff/rules/#flake8-bugbear-b
+    "C4",  # flake8-comprehensions - https://docs.astral.sh/ruff/rules/#flake8-comprehensions-c4
+    "E",   # pycodestyle errors - https://docs.astral.sh/ruff/rules/#error-e
+    "F",   # pyflakes rules - https://docs.astral.sh/ruff/rules/#pyflakes-f
+    "W",   # pycodestyle warnings - https://docs.astral.sh/ruff/rules/#warning-w
+    "I",   # isort - https://docs.astral.sh/ruff/rules/#isort-i
+    "UP",  # pyupgrade - https://docs.astral.sh/ruff/rules/#pyupgrade-up
+    "SLF", # self - https://docs.astral.sh/ruff/settings/#lintflake8-self
 ]
+
+[tool.ruff.lint.per-file-ignores]
+# By default, private member access is allowed in tests
+# See https://github.com/DiamondLightSource/python-copier-template/issues/154
+# Remove this line to forbid private member access in tests
+"tests/**/*" = ["SLF001"]