diff --git a/pyproject.toml b/pyproject.toml
index 46cbd3ee4062aebf288381c716ab51d813b0dea4..2184db5ff3dfc836c0472173cc6f2ffd62cceb1f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -14,6 +14,11 @@ classifiers = [
     ]
 dynamic = ["version"] # defined in tool.setuptools_scm
 
+[project.optional-dependencies]
+test = [
+    "pytest"
+]
+
 [build-system]
 requires = [
     "setuptools>=64",