diff --git a/src/service/rooms/timeline/mod.rs b/src/service/rooms/timeline/mod.rs
index affe35ab..df23da8f 100644
--- a/src/service/rooms/timeline/mod.rs
+++ b/src/service/rooms/timeline/mod.rs
@@ -236,11 +236,19 @@ impl Service {
 							"prev_content".to_owned(),
 							CanonicalJsonValue::Object(
 								utils::to_canonical_object(prev_state.content.clone()).map_err(|e| {
-									error!("Failed to convert prev_state to canonical JSON: {}", e);
+									error!("Failed to convert prev_state to canonical JSON: {e}");
 									Error::bad_database("Failed to convert prev_state to canonical JSON.")
 								})?,
 							),
 						);
+						unsigned.insert(
+							String::from("prev_sender"),
+							CanonicalJsonValue::String(prev_state.sender.clone().to_string()),
+						);
+						unsigned.insert(
+							String::from("replaces_state"),
+							CanonicalJsonValue::String(prev_state.event_id.clone().to_string()),
+						);
 					}
 				}
 			} else {
@@ -660,6 +668,10 @@ impl Service {
 					"prev_sender".to_owned(),
 					serde_json::to_value(&prev_pdu.sender).expect("UserId::to_value always works"),
 				);
+				unsigned.insert(
+					"replaces_state".to_owned(),
+					serde_json::to_value(&prev_pdu.event_id).expect("EventId is valid json"),
+				);
 			}
 		}