diff --git a/rowers/tasks.py b/rowers/tasks.py
index 01def2df..f64b6c54 100644
--- a/rowers/tasks.py
+++ b/rowers/tasks.py
@@ -1026,7 +1026,7 @@ def handle_sendemail_breakthrough(workoutid, useremail,
     d = {
         'first_name':userfirstname,
         'siteurl':siteurl,
-        'workoutid':workoutid,
+        'workoutid':encoder.encode_hex(workoutid),
         'btvalues':tablevalues,
         }
 
@@ -1071,7 +1071,7 @@ def handle_sendemail_hard(workoutid, useremail,
     d = {
         'first_name':userfirstname,
         'siteurl':siteurl,
-        'workoutid':workoutid,
+        'workoutid':encoder.encode_hex(workoutid),
         'btvalues':tablevalues,
         }