diff --git a/pyproject.toml b/pyproject.toml
index 93430d668..3079e13d4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -74,6 +74,8 @@ optional = [
   "psycopg[binary]>=3.1.8",
   "pygments>=2.17,<2.20",
   "pyyaml>=5.3.1,<6.1",
+  # setuptools is needed for coreapi (imports pkg_resources)
+  "setuptools",
 ]
 django42 = [ "django>=4.2,<5.0" ]
 django50 = [ "django>=5.0,<5.1" ]