diff --git a/requirements.txt b/requirements.txt
index 31900962..31c5c84f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,3 +20,4 @@ validators
 ipython
 PyOpenGL
 manimpango>=0.2.0,<0.4.0
+cssselect2
diff --git a/setup.cfg b/setup.cfg
index 566c638a..c5164886 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -39,6 +39,7 @@ install_requires =
     ipython
     PyOpenGL
     manimpango>=0.2.0,<0.4.0
+    cssselect2
 
 [options.entry_points]
 console_scripts =