diff --git a/rowers/integrations/intervals.py b/rowers/integrations/intervals.py
index e0692a57..66fdb0d5 100644
--- a/rowers/integrations/intervals.py
+++ b/rowers/integrations/intervals.py
@@ -18,6 +18,7 @@ from uuid import uuid4
 from django.utils import timezone
 from datetime import timedelta
 import rowers.dataprep as dataprep
+from rowers.opaque import encoder
 
 from rowsandall_app.settings import (
     INTERVALS_CLIENT_ID, INTERVALS_REDIRECT_URI, INTERVALS_CLIENT_SECRET, SITE_URL
@@ -171,6 +172,7 @@ class IntervalsIntegration(SyncIntegration):
         params = {
             'name': workout.name,
             'description': workout.notes,
+            'external_id': encoder.encode_hex(workout.id),
             }
 
 
diff --git a/rowers/tests/testdata/testdata.tcx.gz b/rowers/tests/testdata/testdata.tcx.gz
index 5c4f915d..3a360014 100644
Binary files a/rowers/tests/testdata/testdata.tcx.gz and b/rowers/tests/testdata/testdata.tcx.gz differ