diff --git a/krebs/3modules/urlwatch.nix b/krebs/3modules/urlwatch.nix
index 8ebbdd1f8..113f6e65d 100644
--- a/krebs/3modules/urlwatch.nix
+++ b/krebs/3modules/urlwatch.nix
@@ -181,8 +181,11 @@ let
                   sed '1!s/^  //'
                 )
                 echo To: ${shell.escape cfg.mailto}
+                echo Mime-Version: 1.0
+                echo Content-Type: text/plain\; charset=UTF-8
+                echo Content-Transfer-Encoding: base64
                 echo
-                cat changes
+                base64 changes
               } | /run/wrappers/bin/sendmail -t
             fi
           ''}