diff --git a/pyproject.toml b/pyproject.toml
index 1e317ef7a..6f29f8c2a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -88,8 +88,9 @@ format-jinja = "{% if distance == 0 %}{{ base }}{% else %}{{ base }}.{{ distance
 [tool.pytest.ini_options]
 minversion = "6.0"
 testpaths = ["tests"]
-addopts = [ "-Werror","-v","--cov=pyfeyn2","--cov-config=.coveragerc","--cov-append","--cov-report=term","--cov-report=xml","--doctest-modules","--ignore=docs/source/conf.py" ]
+addopts = [ "-v","--cov=pyfeyn2","--cov-config=.coveragerc","--cov-append","--cov-report=term","--cov-report=xml","--doctest-modules","--ignore=docs/source/conf.py" ]
 filterwarnings = [
     'error',
-    'ignore: pkg_resources is deprecated as an API:DeprecationWarning'
+    'ignore: pkg_resources is deprecated as an API:DeprecationWarning',
+    'ignore: invalid escape sequence.*:SyntaxError'
 ]