diff --git a/Makefile b/Makefile
index 0a039e5..4ceffd2 100644
--- a/Makefile
+++ b/Makefile
@@ -14,17 +14,15 @@ VENV=xcffib_venv
 PYTHON=$(VENV)/bin/python3
 FLAKE=$(VENV)/bin/flake8
 
+GENERATOR_FILES=$(shell find . -path ./test -prune -false -o -name \*.hs)
+HANDWRITTEN_MODULE_FILES=$(shell find ./module -name \*.py)
+
 # you should have xcb-proto installed to run this
-xcffib: xcffib_py_files xcffib.cabal $(shell find . -path ./test -prune -false -o -name \*.hs)
+xcffib: xcffib.cabal $(GENERATOR_FILES) $(HANDWRITTEN_MODULE_FILES)
 	$(GEN) --input $(XCBDIR) --output ./xcffib
+	cp ./module/*.py ./xcffib/
 	touch ./xcffib/py.typed
-	sed -i -e "s/__xcb_proto_version__ = .*/__xcb_proto_version__ = \"${XCBVER}\"/" xcffib/__init__.py
-
-xcffib_py_files: $(addprefix xcffib/, $(notdir $(wildcard module/*.py)))
-
-xcffib/%.py: module/%.py
-	mkdir -p xcffib/
-	cp $^ $@
+	sed -i "s/__xcb_proto_version__ = .*/__xcb_proto_version__ = \"${XCBVER}\"/" xcffib/__init__.py
 
 .PHONY: xcffib-fmt
 xcffib-fmt: module/*.py
@@ -72,32 +70,12 @@ $(VENV): requirements.txt
 		python -m venv $(VENV)
 		$(PYTHON) -m pip install -r requirements.txt
 
-check-abi: xcffib $(VENV)
-	# check abi precompiled mode
-	# make a temporary env to test install and ensure we cd somewhere
-	# we won't pick up the local source xcffib module
-	$(eval TMPLOC=$(shell mktemp -d))
-	python -m venv $(TMPLOC)
-	CC=/bin/false ${TMPLOC}/bin/python -m pip install --no-cache -v .
-	${TMPLOC}/bin/python -m pip install pytest pytest-xdist
-	${TMPLOC}/bin/python -c "import os; os.chdir('${TMPLOC}'); import xcffib; print(xcffib.cffi_mode); assert xcffib.cffi_mode == 'abi_precompiled'"
-	${TMPLOC}/bin/python -m pytest -v --durations=3 -n auto
-
-check-api: xcffib $(VENV)
-	# check abi precompiled mode
-	# make a temporary env to test install and ensure we cd somewhere
-	# we won't pick up the local source xcffib module
-	$(eval TMPLOC=$(shell mktemp -d))
-	python -m venv ${TMPLOC}
-	${TMPLOC}/bin/python -m pip install -v --no-cache .
-	${TMPLOC}/bin/python -m pip install pytest pytest-xdist
-	${TMPLOC}/bin/python -c "import os; os.chdir('${TMPLOC}'); import xcffib; print(xcffib.cffi_mode); assert xcffib.cffi_mode == 'api'"
-	${TMPLOC}/bin/python -m pytest -v --durations=3 -n auto
+check-mode-%: xcffib requirements.txt
+	./test/test_mode.sh $*
 
-check: xcffib htests $(VENV) lint check-api check-abi
+check: xcffib htests lint check-mode-api check-mode-abi_precompiled
 	$(CABAL) check
 	$(PYTHON) -m compileall xcffib
-	$(PYTHON) -m pytest -v --durations=3 -n $(NCPUS)
 
 # make release ver=0.99.99
 release: xcffib
diff --git a/test/test_mode.sh b/test/test_mode.sh
new file mode 100755
index 0000000..b5eb84c
--- /dev/null
+++ b/test/test_mode.sh
@@ -0,0 +1,27 @@
+#!/bin/bash -eux
+
+MODE=$1
+
+VENV=$(mktemp -d xcffib-test-$MODE.XXXXXXXXXX)
+
+function cleanup {
+    rm -rf "${VENV}"
+}
+trap cleanup EXIT
+
+# mask CC in abi_precompiled so that we force compilation at runtime
+if [ "${MODE}" == "abi" ] || [ "${MODE}" == "abi_precompiled" ]; then
+    export CC=false
+fi
+
+python -m venv "${VENV}"
+source "${VENV}/bin/activate"
+
+pip install -r requirements.txt
+pip install --no-cache -v .
+
+# make a temporary env to test install and ensure we cd somewhere
+# we won't pick up the local source xcffib module. the venv dir is as good a
+# place as any
+python -I -c "import xcffib; print(\"mode is\", xcffib.cffi_mode, \"path is\", xcffib.__file__); assert xcffib.cffi_mode == \"${MODE}\""
+python -I -m pytest --durations=3 -n auto