diff --git a/sync/src/api.rs b/sync/src/api.rs
index 458b61daa..5b97bc566 100644
--- a/sync/src/api.rs
+++ b/sync/src/api.rs
@@ -674,6 +674,16 @@ impl LightSync {
 			subprotocol_name: params.subprotocol_name,
 		})
 	}
+
+	/// Execute a closure with a protocol context.
+	pub fn with_context<F, T>(&self, f: F) -> Option<T>
+		where F: FnOnce(&::light::net::BasicContext) -> T
+	{
+		self.network.with_context_eval(
+			self.subprotocol_name,
+			move |ctx| self.proto.with_context(ctx, f),
+		)
+	}
 }
 
 impl ManageNetwork for LightSync {
diff --git a/util/network/src/host.rs b/util/network/src/host.rs
index 98efbd6a0..c3f5ab8cf 100644
--- a/util/network/src/host.rs
+++ b/util/network/src/host.rs
@@ -983,14 +983,14 @@ impl Host {
 		self.nodes.write().update(node_changes, &*self.reserved_nodes.read());
 	}
 
-	pub fn with_context<F>(&self, protocol: ProtocolId, io: &IoContext<NetworkIoMessage>, action: F) where F: Fn(&NetworkContext) {
+	pub fn with_context<F>(&self, protocol: ProtocolId, io: &IoContext<NetworkIoMessage>, action: F) where F: FnOnce(&NetworkContext) {
 		let reserved = { self.reserved_nodes.read() };
 
 		let context = NetworkContext::new(io, protocol, None, self.sessions.clone(), &reserved);
 		action(&context);
 	}
 
-	pub fn with_context_eval<F, T>(&self, protocol: ProtocolId, io: &IoContext<NetworkIoMessage>, action: F) -> T where F: Fn(&NetworkContext) -> T {
+	pub fn with_context_eval<F, T>(&self, protocol: ProtocolId, io: &IoContext<NetworkIoMessage>, action: F) -> T where F: FnOnce(&NetworkContext) -> T {
 		let reserved = { self.reserved_nodes.read() };
 
 		let context = NetworkContext::new(io, protocol, None, self.sessions.clone(), &reserved);
diff --git a/util/network/src/service.rs b/util/network/src/service.rs
index 73b5dafb5..76e21c7f8 100644
--- a/util/network/src/service.rs
+++ b/util/network/src/service.rs
@@ -177,7 +177,7 @@ impl NetworkService {
 	}
 
 	/// Executes action in the network context
-	pub fn with_context<F>(&self, protocol: ProtocolId, action: F) where F: Fn(&NetworkContext) {
+	pub fn with_context<F>(&self, protocol: ProtocolId, action: F) where F: FnOnce(&NetworkContext) {
 		let io = IoContext::new(self.io_service.channel(), 0);
 		let host = self.host.read();
 		if let Some(ref host) = host.as_ref() {
@@ -186,7 +186,7 @@ impl NetworkService {
 	}
 
 	/// Evaluates function in the network context
-	pub fn with_context_eval<F, T>(&self, protocol: ProtocolId, action: F) -> Option<T> where F: Fn(&NetworkContext) -> T {
+	pub fn with_context_eval<F, T>(&self, protocol: ProtocolId, action: F) -> Option<T> where F: FnOnce(&NetworkContext) -> T {
 		let io = IoContext::new(self.io_service.channel(), 0);
 		let host = self.host.read();
 		host.as_ref().map(|ref host| host.with_context_eval(protocol, &io, action))