diff --git a/pkgs/by-name/sy/sympa/package.nix b/pkgs/by-name/sy/sympa/package.nix
index bae91b64c82b..f7fdfe270c7c 100644
--- a/pkgs/by-name/sy/sympa/package.nix
+++ b/pkgs/by-name/sy/sympa/package.nix
@@ -47,6 +47,7 @@ let
       TemplateToolkit
       URI
       UnicodeLineBreak
+      UnicodeUTF8
       XMLLibXML
 
       ### Features