diff --git a/Cargo.toml b/Cargo.toml
index dd4cf60c..8e816675 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -91,6 +91,7 @@ unnested_or_patterns = "warn"
 unreadable_literal = "warn"
 unseparated_literal_suffix = "warn"
 unused_async = "warn"
+unused_self = "warn"
 verbose_file_reads = "warn"
 wildcard_dependencies = "warn"
 
diff --git a/src/service/admin.rs b/src/service/admin.rs
index 1a7cd8aa..3d10be63 100644
--- a/src/service/admin.rs
+++ b/src/service/admin.rs
@@ -277,12 +277,12 @@ impl Service {
         let command_line = lines.next().expect("each string has at least one line");
         let body: Vec<_> = lines.collect();
 
-        let admin_command = match self.parse_admin_command(command_line) {
+        let admin_command = match Self::parse_admin_command(command_line) {
             Ok(command) => command,
             Err(error) => {
                 let server_name = services().globals.server_name();
                 let message = error.replace("server.name", server_name.as_str());
-                let html_message = self.usage_to_html(&message, server_name);
+                let html_message = Self::usage_to_html(&message, server_name);
 
                 return RoomMessageEventContent::text_html(message, html_message);
             }
@@ -306,7 +306,7 @@ impl Service {
     }
 
     // Parse chat messages from the admin room into an AdminCommand object
-    fn parse_admin_command(&self, command_line: &str) -> std::result::Result<AdminCommand, String> {
+    fn parse_admin_command(command_line: &str) -> std::result::Result<AdminCommand, String> {
         // Note: argv[0] is `@grapevine:servername:`, which is treated as the main command
         let mut argv: Vec<_> = command_line.split_whitespace().collect();
 
@@ -864,7 +864,7 @@ impl Service {
     }
 
     // Utility to turn clap's `--help` text to HTML.
-    fn usage_to_html(&self, text: &str, server_name: &ServerName) -> String {
+    fn usage_to_html(text: &str, server_name: &ServerName) -> String {
         // Replace `@grapevine:servername:-subcmdname` with `@grapevine:servername: subcmdname`
         let text = text.replace(
             &format!("@grapevine:{server_name}:-"),
@@ -1183,6 +1183,8 @@ impl Service {
     /// Gets the room ID of the admin room
     ///
     /// Errors are propagated from the database, and will have None if there is no admin room
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     pub(crate) fn get_admin_room(&self) -> Result<Option<OwnedRoomId>> {
         let admin_room_alias: Box<RoomAliasId> =
             format!("#admins:{}", services().globals.server_name())
diff --git a/src/service/media.rs b/src/service/media.rs
index c19497cf..7b12ab1f 100644
--- a/src/service/media.rs
+++ b/src/service/media.rs
@@ -86,7 +86,7 @@ impl Service {
 
     /// Returns width, height of the thumbnail and whether it should be cropped. Returns None when
     /// the server should send the original file.
-    pub(crate) fn thumbnail_properties(&self, width: u32, height: u32) -> Option<(u32, u32, bool)> {
+    fn thumbnail_properties(width: u32, height: u32) -> Option<(u32, u32, bool)> {
         match (width, height) {
             (0..=32, 0..=32) => Some((32, 32, true)),
             (0..=96, 0..=96) => Some((96, 96, true)),
@@ -113,9 +113,8 @@ impl Service {
         width: u32,
         height: u32,
     ) -> Result<Option<FileMeta>> {
-        let (width, height, crop) = self
-            .thumbnail_properties(width, height)
-            .unwrap_or((0, 0, false)); // 0, 0 because that's the original file
+        let (width, height, crop) =
+            Self::thumbnail_properties(width, height).unwrap_or((0, 0, false)); // 0, 0 because that's the original file
 
         if let Ok((content_disposition, content_type, key)) =
             self.db.search_file_metadata(mxc.clone(), width, height)
diff --git a/src/service/rooms/event_handler.rs b/src/service/rooms/event_handler.rs
index f86465ed..9e6b4802 100644
--- a/src/service/rooms/event_handler.rs
+++ b/src/service/rooms/event_handler.rs
@@ -132,7 +132,7 @@ impl Service {
                 pub_key_map,
             )
             .await?;
-        self.check_room_id(room_id, &incoming_pdu)?;
+        Self::check_room_id(room_id, &incoming_pdu)?;
 
         // 8. if not timeline event: stop
         if !is_timeline_event {
@@ -375,7 +375,7 @@ impl Service {
             )
             .map_err(|_| Error::bad_database("Event is not a valid PDU."))?;
 
-            self.check_room_id(room_id, &incoming_pdu)?;
+            Self::check_room_id(room_id, &incoming_pdu)?;
 
             if !auth_events_known {
                 // 4. fetch any missing auth events doing all checks listed here starting at 1. These are not timeline events
@@ -411,7 +411,7 @@ impl Service {
                     continue;
                 };
 
-                self.check_room_id(room_id, &auth_event)?;
+                Self::check_room_id(room_id, &auth_event)?;
 
                 match auth_events.entry((
                     auth_event.kind.to_string().into(),
@@ -1287,7 +1287,7 @@ impl Service {
                 .await
                 .pop()
             {
-                self.check_room_id(room_id, &pdu)?;
+                Self::check_room_id(room_id, &pdu)?;
 
                 if amount > services().globals.max_fetch_prev_events() {
                     // Max limit reached
@@ -1612,6 +1612,8 @@ impl Service {
     }
 
     /// Returns Ok if the acl allows the server
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     pub(crate) fn acl_check(&self, server_name: &ServerName, room_id: &RoomId) -> Result<()> {
         let Some(acl_event) = services().rooms.state_accessor.room_state_get(
             room_id,
@@ -1815,7 +1817,7 @@ impl Service {
         ))
     }
 
-    fn check_room_id(&self, room_id: &RoomId, pdu: &PduEvent) -> Result<()> {
+    fn check_room_id(room_id: &RoomId, pdu: &PduEvent) -> Result<()> {
         if pdu.room_id != room_id {
             warn!("Found event from room {} in room {}", pdu.room_id, room_id);
             return Err(Error::BadRequest(
diff --git a/src/service/rooms/pdu_metadata.rs b/src/service/rooms/pdu_metadata.rs
index e9060ae7..13f29663 100644
--- a/src/service/rooms/pdu_metadata.rs
+++ b/src/service/rooms/pdu_metadata.rs
@@ -40,7 +40,11 @@ impl Service {
         }
     }
 
-    #[allow(clippy::too_many_arguments)]
+    #[allow(
+        clippy::too_many_arguments,
+        // Allowed because this function uses `services()`
+        clippy::unused_self,
+    )]
     pub(crate) fn paginate_relations_with_filter(
         &self,
         sender_user: &UserId,
diff --git a/src/service/rooms/spaces.rs b/src/service/rooms/spaces.rs
index 0ffbbf9a..bd1f5702 100644
--- a/src/service/rooms/spaces.rs
+++ b/src/service/rooms/spaces.rs
@@ -415,7 +415,7 @@ impl Service {
                     ));
                 }
 
-                self.translate_joinrule(&join_rule)?
+                Self::translate_joinrule(&join_rule)?
             },
             room_type: services()
                 .rooms
@@ -436,7 +436,7 @@ impl Service {
         })
     }
 
-    fn translate_joinrule(&self, join_rule: &JoinRule) -> Result<SpaceRoomJoinRule> {
+    fn translate_joinrule(join_rule: &JoinRule) -> Result<SpaceRoomJoinRule> {
         match join_rule {
             JoinRule::Invite => Ok(SpaceRoomJoinRule::Invite),
             JoinRule::Knock => Ok(SpaceRoomJoinRule::Knock),
@@ -448,6 +448,8 @@ impl Service {
         }
     }
 
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     fn handle_simplified_join_rule(
         &self,
         join_rule: &SpaceRoomJoinRule,
@@ -473,7 +475,7 @@ impl Service {
         room_id: &RoomId,
     ) -> Result<bool> {
         if self.handle_simplified_join_rule(
-            &self.translate_joinrule(join_rule)?,
+            &Self::translate_joinrule(join_rule)?,
             sender_user,
             room_id,
         )? {
diff --git a/src/service/rooms/state_accessor.rs b/src/service/rooms/state_accessor.rs
index 4ed4d43f..6c1dd527 100644
--- a/src/service/rooms/state_accessor.rs
+++ b/src/service/rooms/state_accessor.rs
@@ -282,10 +282,7 @@ impl Service {
     }
 
     pub(crate) fn get_name(&self, room_id: &RoomId) -> Result<Option<String>> {
-        services()
-            .rooms
-            .state_accessor
-            .room_state_get(room_id, &StateEventType::RoomName, "")?
+        self.room_state_get(room_id, &StateEventType::RoomName, "")?
             .map_or(Ok(None), |s| {
                 serde_json::from_str(s.content.get())
                     .map(|c: RoomNameEventContent| Some(c.name))
@@ -300,16 +297,15 @@ impl Service {
     }
 
     pub(crate) fn get_avatar(&self, room_id: &RoomId) -> Result<JsOption<RoomAvatarEventContent>> {
-        services()
-            .rooms
-            .state_accessor
-            .room_state_get(room_id, &StateEventType::RoomAvatar, "")?
+        self.room_state_get(room_id, &StateEventType::RoomAvatar, "")?
             .map_or(Ok(JsOption::Undefined), |s| {
                 serde_json::from_str(s.content.get())
                     .map_err(|_| Error::bad_database("Invalid room avatar event in database."))
             })
     }
 
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     pub(crate) fn user_can_invite(
         &self,
         room_id: &RoomId,
@@ -340,10 +336,7 @@ impl Service {
         room_id: &RoomId,
         user_id: &UserId,
     ) -> Result<Option<RoomMemberEventContent>> {
-        services()
-            .rooms
-            .state_accessor
-            .room_state_get(room_id, &StateEventType::RoomMember, user_id.as_str())?
+        self.room_state_get(room_id, &StateEventType::RoomMember, user_id.as_str())?
             .map_or(Ok(None), |s| {
                 serde_json::from_str(s.content.get())
                     .map_err(|_| Error::bad_database("Invalid room member event in database."))
diff --git a/src/service/rooms/state_compressor.rs b/src/service/rooms/state_compressor.rs
index 8ba07634..8881c652 100644
--- a/src/service/rooms/state_compressor.rs
+++ b/src/service/rooms/state_compressor.rs
@@ -89,6 +89,8 @@ impl Service {
         }
     }
 
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     pub(crate) fn compress_state_event(
         &self,
         shortstatekey: u64,
@@ -106,6 +108,8 @@ impl Service {
     }
 
     /// Returns shortstatekey, event id
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     pub(crate) fn parse_compressed_state_event(
         &self,
         compressed_event: &CompressedStateEvent,
diff --git a/src/service/rooms/timeline.rs b/src/service/rooms/timeline.rs
index cb5f3332..1c57369d 100644
--- a/src/service/rooms/timeline.rs
+++ b/src/service/rooms/timeline.rs
@@ -662,7 +662,7 @@ impl Service {
         // Our depth is the maximum depth of prev_events + 1
         let depth = prev_events
             .iter()
-            .filter_map(|event_id| Some(services().rooms.timeline.get_pdu(event_id).ok()??.depth))
+            .filter_map(|event_id| Some(self.get_pdu(event_id).ok()??.depth))
             .max()
             .unwrap_or_else(|| uint!(0))
             + uint!(1);
diff --git a/src/service/users.rs b/src/service/users.rs
index 2e52f478..53882040 100644
--- a/src/service/users.rs
+++ b/src/service/users.rs
@@ -260,6 +260,8 @@ impl Service {
     }
 
     /// Check if a user is an admin
+    // Allowed because this function uses `services()`
+    #[allow(clippy::unused_self)]
     pub(crate) fn is_admin(&self, user_id: &UserId) -> Result<bool> {
         let admin_room_alias_id =
             RoomAliasId::parse(format!("#admins:{}", services().globals.server_name()))