diff --git a/crates/matrix-sdk-crypto/src/store/memorystore.rs b/crates/matrix-sdk-crypto/src/store/memorystore.rs
index 00385a140..395b54bbc 100644
--- a/crates/matrix-sdk-crypto/src/store/memorystore.rs
+++ b/crates/matrix-sdk-crypto/src/store/memorystore.rs
@@ -55,6 +55,7 @@ pub struct MemoryStore {
     sessions: SessionStore,
     inbound_group_sessions: GroupSessionStore,
     outbound_group_sessions: StdRwLock<BTreeMap<OwnedRoomId, OutboundGroupSession>>,
+    tracked_users: StdRwLock<Vec<TrackedUser>>,
     olm_hashes: StdRwLock<HashMap<String, HashSet<String>>>,
     devices: DeviceStore,
     identities: StdRwLock<HashMap<OwnedUserId, ReadOnlyUserIdentities>>,
@@ -76,6 +77,7 @@ impl Default for MemoryStore {
             sessions: SessionStore::new(),
             inbound_group_sessions: GroupSessionStore::new(),
             outbound_group_sessions: Default::default(),
+            tracked_users: Default::default(),
             olm_hashes: Default::default(),
             devices: DeviceStore::new(),
             identities: Default::default(),
@@ -315,10 +317,13 @@ impl CryptoStore for MemoryStore {
     }
 
     async fn load_tracked_users(&self) -> Result<Vec<TrackedUser>> {
-        Ok(Vec::new())
+        Ok(self.tracked_users.read().unwrap().clone())
     }
 
-    async fn save_tracked_users(&self, _: &[(&UserId, bool)]) -> Result<()> {
+    async fn save_tracked_users(&self, tracked_users: &[(&UserId, bool)]) -> Result<()> {
+        self.tracked_users.write().unwrap().extend(tracked_users.iter().map(|(user_id, dirty)| {
+            TrackedUser { user_id: user_id.to_owned().into(), dirty: *dirty }
+        }));
         Ok(())
     }
 
@@ -472,7 +477,7 @@ impl CryptoStore for MemoryStore {
 #[cfg(test)]
 mod tests {
     use matrix_sdk_test::async_test;
-    use ruma::room_id;
+    use ruma::{room_id, user_id};
     use vodozemac::{Curve25519PublicKey, Ed25519PublicKey};
 
     use crate::{
@@ -526,7 +531,7 @@ mod tests {
 
     #[async_test]
     async fn test_outbound_group_session_store() {
-        // Given an outbound sessions
+        // Given an outbound session
         let (account, _) = get_account_and_session_test_helper();
         let room_id = room_id!("!test:localhost");
         let (outbound, _) = account.create_group_session_pair_with_defaults(room_id).await;
@@ -543,6 +548,26 @@ mod tests {
         );
     }
 
+    #[async_test]
+    async fn test_tracked_users_store() {
+        // Given some tracked users
+        let tracked_users =
+            &[(user_id!("@dirty_user:s"), true), (user_id!("@clean_user:t"), false)];
+
+        // When we save them to the store
+        let store = MemoryStore::new();
+        store.save_tracked_users(tracked_users).await.unwrap();
+
+        // Then we can get them out again
+        let loaded_tracked_users =
+            store.load_tracked_users().await.expect("failed to load tracked users");
+        assert_eq!(loaded_tracked_users[0].user_id, user_id!("@dirty_user:s"));
+        assert!(loaded_tracked_users[0].dirty);
+        assert_eq!(loaded_tracked_users[1].user_id, user_id!("@clean_user:t"));
+        assert!(!loaded_tracked_users[1].dirty);
+        assert_eq!(loaded_tracked_users.len(), 2);
+    }
+
     #[async_test]
     async fn test_device_store() {
         let device = get_device();
diff --git a/crates/matrix-sdk-crypto/src/store/mod.rs b/crates/matrix-sdk-crypto/src/store/mod.rs
index 67969a0e2..5ae09a509 100644
--- a/crates/matrix-sdk-crypto/src/store/mod.rs
+++ b/crates/matrix-sdk-crypto/src/store/mod.rs
@@ -526,7 +526,7 @@ pub struct Changes {
 }
 
 /// A user for which we are tracking the list of devices.
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct TrackedUser {
     /// The user ID of the user.
     pub user_id: OwnedUserId,