diff --git a/requirements.txt b/requirements.txt
index 9af70daa..72a40933 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,6 +12,7 @@ plyer             >= 1.4.3,  < 2
 sortedcontainers  >= 2.2.2,  < 3
 watchgod          >= 0.6,    < 0.7
 redbaron          >= 0.9.2,  < 1
+hsluv             >= 5.0.0,  < 6
 dbus-python       >= 1.2.16, < 2; platform_system == "Linux"
 
 async_generator   >= 1.10,  < 2;   python_version < "3.7"