diff --git a/src/service/rooms/event_handler/mod.rs b/src/service/rooms/event_handler/mod.rs
index bf553d5c..9490a404 100644
--- a/src/service/rooms/event_handler/mod.rs
+++ b/src/service/rooms/event_handler/mod.rs
@@ -3,6 +3,7 @@ mod signing_keys;
 
 use std::{
 	collections::{hash_map, BTreeMap, HashMap, HashSet},
+	fmt::Write,
 	pin::Pin,
 	sync::{Arc, RwLock as StdRwLock},
 	time::Instant,
@@ -61,6 +62,20 @@ impl crate::Service for Service {
 		}))
 	}
 
+	fn memory_usage(&self, out: &mut dyn Write) -> Result<()> {
+		let mutex_federation = self.mutex_federation.len();
+		writeln!(out, "federation_mutex: {mutex_federation}")?;
+
+		let federation_handletime = self
+			.federation_handletime
+			.read()
+			.expect("locked for reading")
+			.len();
+		writeln!(out, "federation_handletime: {federation_handletime}")?;
+
+		Ok(())
+	}
+
 	fn name(&self) -> &str { crate::service::make_name(std::module_path!()) }
 }
 
diff --git a/src/service/rooms/state/mod.rs b/src/service/rooms/state/mod.rs
index 7d89ee33..a3a317a5 100644
--- a/src/service/rooms/state/mod.rs
+++ b/src/service/rooms/state/mod.rs
@@ -2,6 +2,7 @@ mod data;
 
 use std::{
 	collections::{HashMap, HashSet},
+	fmt::Write,
 	sync::Arc,
 };
 
@@ -40,6 +41,13 @@ impl crate::Service for Service {
 		}))
 	}
 
+	fn memory_usage(&self, out: &mut dyn Write) -> Result<()> {
+		let mutex = self.mutex.len();
+		writeln!(out, "state_mutex: {mutex}")?;
+
+		Ok(())
+	}
+
 	fn name(&self) -> &str { crate::service::make_name(std::module_path!()) }
 }
 
diff --git a/src/service/rooms/timeline/mod.rs b/src/service/rooms/timeline/mod.rs
index df2d46bd..e255e978 100644
--- a/src/service/rooms/timeline/mod.rs
+++ b/src/service/rooms/timeline/mod.rs
@@ -92,6 +92,9 @@ impl crate::Service for Service {
 			.len();
 		writeln!(out, "lasttimelinecount_cache: {lasttimelinecount_cache}")?;
 
+		let mutex_insert = self.mutex_insert.len();
+		writeln!(out, "insert_mutex: {mutex_insert}")?;
+
 		Ok(())
 	}