diff --git a/Makefile b/Makefile
index 2380bb43..5197f626 100644
--- a/Makefile
+++ b/Makefile
@@ -35,7 +35,7 @@ endif
 
 tests: venv
 	$(PIP_INSTALL) pip
-	$(PIP_INSTALL) dist/*.whl
+	$(PIP_INSTALL) --force-reinstall dist/*.whl
 	$(PIP_INSTALL) pytest scipy
 	$(PY.TEST) $(CODE_DIR)/tests