diff --git a/Makefile b/Makefile
index d4e504d..d443321 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
 dist: setup.py lektor_groupby/*
+	[ -z "$${VIRTUAL_ENV}" ]  # you can not do this inside a virtual environment.
 	@echo Building...
 	python3 setup.py sdist bdist_wheel
 	rm -rf ./*.egg-info/ ./build/ MANIFEST
diff --git a/examples/Examples.lektorproject b/examples/Examples.lektorproject
index e88801b..5dc111b 100644
--- a/examples/Examples.lektorproject
+++ b/examples/Examples.lektorproject
@@ -2,4 +2,4 @@
 name = GroupBy Examples
 
 [packages]
-lektor-groupby = 0.9.7
+lektor-groupby = 0.9.8
diff --git a/setup.py b/setup.py
index ec02a53..74c2527 100644
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,7 @@ setup(
     },
     author='relikd',
     url='https://github.com/relikd/lektor-groupby-plugin',
-    version='0.9.7',
+    version='0.9.8',
     description='Cluster arbitrary records with field attribute keyword.',
     long_description=longdesc,
     long_description_content_type="text/markdown",