diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 2abd4f7..44b14d5 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,6 +1,9 @@
 name: build
 
-on: [ push ]
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
 
 jobs:
   build:
diff --git a/Makefile b/Makefile
index 2f5501c..500a6d8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,24 +1,25 @@
+PYTHON ?= python3
 
 all:
-	python setup.py sdist
-	python -m doctest ./customerio/__init__.py
+	$(PYTHON) setup.py sdist
+	$(PYTHON) -m doctest ./customerio/__init__.py
 
 install:
-	python setup.py install
+	$(PYTHON) setup.py install
 
 clean:
-	python setup.py clean
+	$(PYTHON) setup.py clean
 	rm -rf MANIFEST build dist
 
 dev: clean all
 	if ! pip uninstall customerio; then echo "customerio not installed, installing it for the first time" ; fi
 	pip install dist/*
-	python -i -c "from customerio import *"
+	$(PYTHON) -i -c "from customerio import *"
 
 upload:
-	python setup.py register
+	$(PYTHON) setup.py register
 	echo "*** Now upload the binary to PyPi *** (one second)" && sleep 3 && open dist & open "http://pypi.python.org/pypi?%3Aaction=pkg_edit&name=customerio" # python setup.py upload
 
 test:
 	openssl req -new -newkey rsa:2048 -days 10 -nodes -x509 -subj "/C=CA/ST=Ontario/L=Toronto/O=Test/CN=127.0.0.1" -keyout ./tests/server.pem -out ./tests/server.pem
-	python -m unittest discover -v
+	$(PYTHON) -m unittest discover -v