diff --git a/pretalx_salesforce/models.py b/pretalx_salesforce/models.py
index 69743c0..b0be880 100644
--- a/pretalx_salesforce/models.py
+++ b/pretalx_salesforce/models.py
@@ -149,6 +149,7 @@ def serialize_relations(self):
                     "Session__c": {"pretalx_LegacyID__c": self.submission.code},
                     "Contact__c": {"pretalx_LegacyID__c": speaker.code},
                     "Name": f"{speaker.name} – {self.submission.title}",
+                    "pretalx_LegacyID__c": f"{speaker.code}-{self.submission.code}",
                 }
                 for speaker in self.submission.speakers.all()
             ]