diff --git a/src/database/sending.rs b/src/database/sending.rs
index 187fd57..77998e7 100644
--- a/src/database/sending.rs
+++ b/src/database/sending.rs
@@ -36,6 +36,12 @@ impl Sending {
                         let pdu_id = parts.next().ok_or_else(|| Error::bad_database("Invalid serverpduid in db."))?;
                         let mut pdu_json = rooms.get_pdu_json_from_id(&pdu_id.into())?.ok_or_else(|| Error::bad_database("Event in serverpduids not found in db."))?;
 
+                        if let Some(unsigned) = pdu_json
+                            .as_object_mut()
+                            .expect("json is object")
+                            .get_mut("unsigned") {
+                                unsigned.as_object_mut().expect("unsigned is object").remove("transaction_id");
+                        }
                         pdu_json
                             .as_object_mut()
                             .expect("json is object")
diff --git a/src/pdu.rs b/src/pdu.rs
index 6d78092..957d9e0 100644
--- a/src/pdu.rs
+++ b/src/pdu.rs
@@ -201,6 +201,9 @@ impl PduEvent {
     }
 
     pub fn to_outgoing_federation_event(&self) -> Raw<PduStub> {
+        let mut unsigned = self.unsigned.clone();
+        unsigned.remove("transaction_id");
+
         let mut json = json!({
             "room_id": self.room_id,
             "sender": self.sender,
@@ -210,7 +213,7 @@ impl PduEvent {
             "prev_events": self.prev_events,
             "depth": self.depth,
             "auth_events": self.auth_events,
-            "unsigned": self.unsigned,
+            "unsigned": unsigned,
             "hashes": self.hashes,
             "signatures": self.signatures,
         });