diff --git a/requirements.txt b/requirements.txt
index 927036d5e22b9310d0b8d103995982d5688f0136..723b96efae55a831a34a2dd887e4d1ab9a1e15f1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,6 +10,7 @@ greenlet==0.4.10 ; python_version < '3.7'
 greenlet==0.4.13 ; python_version >= '3.7'
 html2text==2016.9.19
 Jinja2==2.10.1
+libsass==0.12.3
 lxml==3.7.1 ; sys_platform != 'win32' and python_version < '3.7'
 lxml==4.2.3 ; sys_platform != 'win32' and python_version >= '3.7'
 lxml ; sys_platform == 'win32'