diff --git a/Makefile b/Makefile
index 961b821..48156df 100644
--- a/Makefile
+++ b/Makefile
@@ -123,6 +123,8 @@ install: install-core install-dev
 
 # Install from source (editable mode) for development and testing.
 install-source-dev-and-test: venv
+	@echo "Ensuring setuptools is installed (required by Pyramid on Python 3.12+)..."
+	$(PIP) install setuptools
 	@echo "Installing make_post_sell from source (editable mode) for development..."
 	$(PIP) install --editable .
 	$(PIP) install --upgrade -r requirements-dev.txt
@@ -130,6 +132,8 @@ install-source-dev-and-test: venv
 
 # Install from source for production (non‑editable).
 install-source-prod: venv
+	@echo "Ensuring setuptools is installed (required by Pyramid on Python 3.12+)..."
+	$(PIP) install setuptools
 	@echo "Deleting tests from source code for production..."
 	rm -rf make_post_sell/tests
 	@echo "Installing make_post_sell from source for production (non‑editable)..."