diff --git a/setup.py b/setup.py
index e32effa9..e47ac7a3 100755
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@ def get_version():
 
 EXTRAS_REQUIRE = {
     "css": [
-        "tinycss2>=1.1.0<1.2",
+        "tinycss2>=1.1.0,<1.2",
     ],
     "dev": [
         "pip-tools==6.5.1",