diff --git a/src/state_event.rs b/src/state_event.rs
index 7b94ae84..b9ab4e40 100644
--- a/src/state_event.rs
+++ b/src/state_event.rs
@@ -260,7 +260,7 @@ impl StateEvent {
         }
     }
 
-    pub fn signatures(&self) -> BTreeMap<Box<ServerName>, BTreeMap<String, String>> {
+    pub fn signatures(&self) -> BTreeMap<Box<ServerName>, BTreeMap<ruma::ServerKeyId, String>> {
         match self {
             Self::Full(ev) => match ev {
                 Pdu::RoomV1Pdu(_) => maplit::btreemap! {},