diff --git a/src/core/utils/mutex_map.rs b/src/core/utils/mutex_map.rs
index cc593014..2b9e59c6 100644
--- a/src/core/utils/mutex_map.rs
+++ b/src/core/utils/mutex_map.rs
@@ -1,4 +1,5 @@
 use std::{
+	borrow::ToOwned,
 	fmt::Debug,
 	hash::Hash,
 	sync::{Arc, TryLockError::WouldBlock},
@@ -38,17 +39,15 @@ where
 	}
 
 	#[tracing::instrument(level = "trace", skip(self))]
-	pub async fn lock<'a, K>(&'a self, k: &'a K) -> Guard<Key, Val>
+	pub async fn lock<K>(&self, k: &K) -> Guard<Key, Val>
 	where
-		K: Debug + Send + ?Sized + Sync,
-		Key: TryFrom<&'a K>,
-		<Key as TryFrom<&'a K>>::Error: Debug,
+		K: Debug + Send + ?Sized + Sync + ToOwned<Owned = Key>,
 	{
 		let val = self
 			.map
 			.lock()
 			.expect("locked")
-			.entry(k.try_into().expect("failed to construct key"))
+			.entry(k.to_owned())
 			.or_default()
 			.clone();
 
@@ -59,17 +58,15 @@ where
 	}
 
 	#[tracing::instrument(level = "trace", skip(self))]
-	pub fn try_lock<'a, K>(&self, k: &'a K) -> Result<Guard<Key, Val>>
+	pub fn try_lock<K>(&self, k: &K) -> Result<Guard<Key, Val>>
 	where
-		K: Debug + Send + ?Sized + Sync,
-		Key: TryFrom<&'a K>,
-		<Key as TryFrom<&'a K>>::Error: Debug,
+		K: Debug + Send + ?Sized + Sync + ToOwned<Owned = Key>,
 	{
 		let val = self
 			.map
 			.lock()
 			.expect("locked")
-			.entry(k.try_into().expect("failed to construct key"))
+			.entry(k.to_owned())
 			.or_default()
 			.clone();
 
@@ -82,11 +79,9 @@ where
 	}
 
 	#[tracing::instrument(level = "trace", skip(self))]
-	pub fn try_try_lock<'a, K>(&self, k: &'a K) -> Result<Guard<Key, Val>>
+	pub fn try_try_lock<K>(&self, k: &K) -> Result<Guard<Key, Val>>
 	where
-		K: Debug + Send + ?Sized + Sync,
-		Key: TryFrom<&'a K>,
-		<Key as TryFrom<&'a K>>::Error: Debug,
+		K: Debug + Send + ?Sized + Sync + ToOwned<Owned = Key>,
 	{
 		let val = self
 			.map
@@ -95,7 +90,7 @@ where
 				| WouldBlock => err!("would block"),
 				| _ => panic!("{e:?}"),
 			})?
-			.entry(k.try_into().expect("failed to construct key"))
+			.entry(k.to_owned())
 			.or_default()
 			.clone();
 
diff --git a/src/service/resolver/actual.rs b/src/service/resolver/actual.rs
index 213f3aba..541668aa 100644
--- a/src/service/resolver/actual.rs
+++ b/src/service/resolver/actual.rs
@@ -43,7 +43,7 @@ impl super::Service {
 			return Ok((result, true));
 		}
 
-		let _dedup = self.resolving.lock(server_name.as_str());
+		let _dedup = self.resolving.lock(server_name);
 		if let Ok(result) = self.cache.get_destination(server_name).await {
 			return Ok((result, true));
 		}
diff --git a/src/service/resolver/mod.rs b/src/service/resolver/mod.rs
index 14f7f2a2..0980a21b 100644
--- a/src/service/resolver/mod.rs
+++ b/src/service/resolver/mod.rs
@@ -9,7 +9,8 @@ mod well_known;
 use std::sync::Arc;
 
 use async_trait::async_trait;
-use tuwunel_core::{Result, arrayvec::ArrayString, smallstr::SmallString, utils::MutexMap};
+use ruma::OwnedServerName;
+use tuwunel_core::{Result, smallstr::SmallString, utils::MutexMap};
 
 use self::{cache::Cache, dns::Resolver, fed::FedDest};
 
@@ -21,8 +22,7 @@ pub struct Service {
 }
 
 pub(crate) type DestString = SmallString<[u8; 40]>;
-type Resolving = MutexMap<NameBuf, ()>;
-type NameBuf = ArrayString<256>;
+type Resolving = MutexMap<OwnedServerName, ()>;
 
 #[async_trait]
 impl crate::Service for Service {