diff --git a/src/key/verification.rs b/src/key/verification.rs
index 32e12197..0d44031e 100644
--- a/src/key/verification.rs
+++ b/src/key/verification.rs
@@ -7,7 +7,7 @@ use serde::{Deserialize, Serialize};
 pub mod accept;
 pub mod cancel;
 pub mod key;
-// pub mod mac;
+pub mod mac;
 pub mod request;
 pub mod start;
 
diff --git a/src/key/verification/mac.rs b/src/key/verification/mac.rs
index 27927e31..d59e7ba2 100644
--- a/src/key/verification/mac.rs
+++ b/src/key/verification/mac.rs
@@ -1,7 +1,8 @@
 //! Types for the *m.key.verification.mac* event.
 
+use std::collections::HashMap;
+
 use ruma_events_macros::ruma_event;
-use ruma_signatures::SignatureSet;
 
 ruma_event! {
     /// Sends the MAC of a device's key to the partner device.
@@ -19,7 +20,7 @@ ruma_event! {
             /// A map of the key ID to the MAC of the key, using the algorithm in the verification process.
             ///
             /// The MAC is encoded as unpadded Base64.
-            pub mac: SignatureSet,
+            pub mac: HashMap<String, String>,
 
             /// The MAC of the comma-separated, sorted, list of key IDs given in the `mac` property, encoded
             /// as unpadded Base64.