diff --git a/bindings/matrix-sdk-ffi/src/notification_settings.rs b/bindings/matrix-sdk-ffi/src/notification_settings.rs
index 30b5641cd..56ba15c3a 100644
--- a/bindings/matrix-sdk-ffi/src/notification_settings.rs
+++ b/bindings/matrix-sdk-ffi/src/notification_settings.rs
@@ -137,13 +137,13 @@ impl NotificationSettings {
     ///
     /// * `room_id` - the room ID
     /// * `is_encrypted` - whether the room is encrypted
-    /// * `active_members_count` - the room's active members count (joined +
-    ///   invited)
+    /// * `is_one_to_one` - whether the room is a direct chat involving two
+    ///   people
     pub async fn get_room_notification_settings(
         &self,
         room_id: String,
         is_encrypted: bool,
-        active_members_count: u64,
+        is_one_to_one: bool,
     ) -> Result<RoomNotificationSettings, NotificationSettingsError> {
         let notification_settings = self.sdk_notification_settings.read().await;
         let parsed_room_id = RoomId::parse(&room_id)
@@ -158,7 +158,7 @@ impl NotificationSettings {
         // If the user has not defined a notification mode, return the default one for
         // this room
         let mode = notification_settings
-            .get_default_room_notification_mode(is_encrypted.into(), active_members_count)
+            .get_default_room_notification_mode(is_encrypted.into(), is_one_to_one.into())
             .await;
         Ok(RoomNotificationSettings::new(mode.into(), true))
     }
@@ -202,16 +202,16 @@ impl NotificationSettings {
     /// # Arguments
     ///
     /// * `is_encrypted` - whether the room is encrypted
-    /// * `active_members_count` - the room's active members count (joined +
-    ///   invited)
+    /// * `is_one_to_one` - whether the room is a direct chats involving two
+    ///   people
     pub async fn get_default_room_notification_mode(
         &self,
         is_encrypted: bool,
-        active_members_count: u64,
+        is_one_to_one: bool,
     ) -> RoomNotificationMode {
         let notification_settings = self.sdk_notification_settings.read().await;
         let mode = notification_settings
-            .get_default_room_notification_mode(is_encrypted.into(), active_members_count)
+            .get_default_room_notification_mode(is_encrypted.into(), is_one_to_one.into())
             .await;
         mode.into()
     }
@@ -344,17 +344,24 @@ impl NotificationSettings {
     }
 
     /// Unmute a room.
+    ///
+    /// # Arguments
+    ///
+    /// * `room_id` - the room to unmute
+    /// * `is_encrypted` - whether the room is encrypted
+    /// * `is_one_to_one` - whether the room is a direct chat involving two
+    ///   people
     pub async fn unmute_room(
         &self,
         room_id: String,
         is_encrypted: bool,
-        members_count: u64,
+        is_one_to_one: bool,
     ) -> Result<(), NotificationSettingsError> {
         let notification_settings = self.sdk_notification_settings.read().await;
         let parsed_room_id = RoomId::parse(&room_id)
             .map_err(|_e| NotificationSettingsError::InvalidRoomId(room_id))?;
         notification_settings
-            .unmute_room(&parsed_room_id, is_encrypted.into(), members_count)
+            .unmute_room(&parsed_room_id, is_encrypted.into(), is_one_to_one.into())
             .await?;
         Ok(())
     }
diff --git a/crates/matrix-sdk/src/notification_settings/mod.rs b/crates/matrix-sdk/src/notification_settings/mod.rs
index f72933ab3..1ae939ebc 100644
--- a/crates/matrix-sdk/src/notification_settings/mod.rs
+++ b/crates/matrix-sdk/src/notification_settings/mod.rs
@@ -121,13 +121,14 @@ impl NotificationSettings {
     /// # Arguments
     ///
     /// * `is_encrypted` - `Yes` if the room is encrypted
-    /// * `members_count` - the room members count
+    /// * `is_one_to_one` - `Yes` if the room is a direct chat involving two
+    ///   people
     pub async fn get_default_room_notification_mode(
         &self,
         is_encrypted: IsEncrypted,
-        members_count: u64,
+        is_one_to_one: IsOneToOne,
     ) -> RoomNotificationMode {
-        self.rules.read().await.get_default_room_notification_mode(is_encrypted, members_count)
+        self.rules.read().await.get_default_room_notification_mode(is_encrypted, is_one_to_one)
     }
 
     /// Get all room IDs for which a user-defined rule exists.
@@ -289,7 +290,7 @@ impl NotificationSettings {
         &self,
         room_id: &RoomId,
         is_encrypted: IsEncrypted,
-        members_count: u64,
+        is_one_to_one: IsOneToOne,
     ) -> Result<(), NotificationSettingsError> {
         let rules = self.rules.read().await.clone();
 
@@ -302,7 +303,7 @@ impl NotificationSettings {
 
             // Get default mode for this room
             let default_mode =
-                rules.get_default_room_notification_mode(is_encrypted, members_count);
+                rules.get_default_room_notification_mode(is_encrypted, is_one_to_one);
 
             // If the default mode is `Mute`, set it to `AllMessages`
             if default_mode == RoomNotificationMode::Mute {
@@ -518,7 +519,7 @@ mod tests {
 
         let settings = NotificationSettings::new(client, ruleset);
         assert_eq!(
-            settings.get_default_room_notification_mode(IsEncrypted::No, 2).await,
+            settings.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes).await,
             RoomNotificationMode::AllMessages
         );
     }
@@ -537,7 +538,7 @@ mod tests {
 
         let settings = NotificationSettings::new(client.to_owned(), ruleset.to_owned());
         assert_eq!(
-            settings.get_default_room_notification_mode(IsEncrypted::No, 2).await,
+            settings.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes).await,
             RoomNotificationMode::MentionsAndKeywordsOnly
         );
 
@@ -549,7 +550,7 @@ mod tests {
 
         let settings = NotificationSettings::new(client, ruleset);
         assert_eq!(
-            settings.get_default_room_notification_mode(IsEncrypted::No, 2).await,
+            settings.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes).await,
             RoomNotificationMode::MentionsAndKeywordsOnly
         );
     }
@@ -849,7 +850,7 @@ mod tests {
         );
 
         // Unmute the room
-        settings.unmute_room(&room_id, IsEncrypted::Yes, 2).await.unwrap();
+        settings.unmute_room(&room_id, IsEncrypted::Yes, IsOneToOne::Yes).await.unwrap();
 
         // The ruleset must not be modified
         assert_eq!(
@@ -883,7 +884,7 @@ mod tests {
         );
 
         // Unmute the room
-        settings.unmute_room(&room_id, IsEncrypted::No, 2).await.unwrap();
+        settings.unmute_room(&room_id, IsEncrypted::No, IsOneToOne::Yes).await.unwrap();
 
         // The user defined mode must have been removed
         assert!(settings.get_user_defined_room_notification_mode(&room_id).await.is_none());
@@ -898,7 +899,7 @@ mod tests {
         let settings = client.notification_settings().await;
 
         // Unmute the room
-        settings.unmute_room(&room_id, IsEncrypted::No, 2).await.unwrap();
+        settings.unmute_room(&room_id, IsEncrypted::No, IsOneToOne::Yes).await.unwrap();
 
         // The new mode must be `AllMessages`
         assert_eq!(
@@ -934,7 +935,7 @@ mod tests {
 
         let settings = NotificationSettings::new(client, ruleset);
         assert_eq!(
-            settings.get_default_room_notification_mode(IsEncrypted::No, 2).await,
+            settings.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes).await,
             RoomNotificationMode::AllMessages
         );
 
@@ -958,7 +959,7 @@ mod tests {
         // and the new mode returned by `get_default_room_notification_mode()` should
         // reflect the change.
         assert_matches!(
-            settings.get_default_room_notification_mode(IsEncrypted::No, 2).await,
+            settings.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes).await,
             RoomNotificationMode::MentionsAndKeywordsOnly
         );
     }
diff --git a/crates/matrix-sdk/src/notification_settings/rules.rs b/crates/matrix-sdk/src/notification_settings/rules.rs
index a4811d623..1802f1c88 100644
--- a/crates/matrix-sdk/src/notification_settings/rules.rs
+++ b/crates/matrix-sdk/src/notification_settings/rules.rs
@@ -99,17 +99,16 @@ impl Rules {
     ///
     /// # Arguments
     ///
-    /// * `is_encrypted` - `true` if the room is encrypted
-    /// * `members_count` - the room members count
+    /// * `is_encrypted` - `Yes` if the room is encrypted
+    /// * `is_one_to_one` - `Yes` if the room is a direct chat involving two
+    ///   people
     pub(crate) fn get_default_room_notification_mode(
         &self,
         is_encrypted: IsEncrypted,
-        members_count: u64,
+        is_one_to_one: IsOneToOne,
     ) -> RoomNotificationMode {
-        // get the correct default rule ID based on `is_encrypted` and `members_count`
-        let is_one_to_one = members_count == 2;
-        let predefined_rule_id =
-            get_predefined_underride_room_rule_id(is_encrypted, is_one_to_one.into());
+        // get the correct default rule ID based on `is_encrypted` and `is_one_to_one`
+        let predefined_rule_id = get_predefined_underride_room_rule_id(is_encrypted, is_one_to_one);
         let rule_id = predefined_rule_id.as_str();
 
         // If there is an `Underride` rule that should trigger a notification, the mode
@@ -264,7 +263,7 @@ impl Rules {
 /// # Arguments
 ///
 /// * `is_encrypted` - `Yes` if the room is encrypted
-/// * `is_one_to_one` - `Yes` if the room is a direct chat
+/// * `is_one_to_one` - `Yes` if the room is a direct chat involving two people
 pub(crate) fn get_predefined_underride_room_rule_id(
     is_encrypted: IsEncrypted,
     is_one_to_one: IsOneToOne,
@@ -419,7 +418,7 @@ pub(crate) mod tests {
             .unwrap();
 
         let rules = Rules::new(ruleset);
-        let mode = rules.get_default_room_notification_mode(IsEncrypted::No, 2);
+        let mode = rules.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes);
         // Then the mode should be `MentionsAndKeywordsOnly`
         assert_eq!(mode, RoomNotificationMode::MentionsAndKeywordsOnly);
     }
@@ -433,7 +432,7 @@ pub(crate) mod tests {
             .unwrap();
 
         let rules = Rules::new(ruleset);
-        let mode = rules.get_default_room_notification_mode(IsEncrypted::No, 2);
+        let mode = rules.get_default_room_notification_mode(IsEncrypted::No, IsOneToOne::Yes);
         // Then the mode should be `AllMessages`
         assert_eq!(mode, RoomNotificationMode::AllMessages);
     }