diff --git a/ethcore/sync/src/blocks.rs b/ethcore/sync/src/blocks.rs
index c9ec3b513..7d5931150 100644
--- a/ethcore/sync/src/blocks.rs
+++ b/ethcore/sync/src/blocks.rs
@@ -508,7 +508,7 @@ impl BlockCollection {
 	// update subchain headers
 	fn update_heads(&mut self) {
 		let mut new_heads = Vec::new();
-		let old_subchains: HashSet<_> = { self.heads.iter().cloned().collect() };
+		let old_subchains: HashSet<_> = self.heads.iter().cloned().collect();
 		for s in self.heads.drain(..) {
 			let mut h = s.clone();
 			if !self.blocks.contains_key(&h) {
diff --git a/rpc/src/v1/helpers/dispatch/light.rs b/rpc/src/v1/helpers/dispatch/light.rs
index b002b9ba5..153091cfd 100644
--- a/rpc/src/v1/helpers/dispatch/light.rs
+++ b/rpc/src/v1/helpers/dispatch/light.rs
@@ -258,7 +258,7 @@ where
 {
 	const GAS_PRICE_SAMPLE_SIZE: usize = 100;
 
-	if let Some(cached) = { cache.lock().gas_price_corpus() } {
+	if let Some(cached) = cache.lock().gas_price_corpus() {
 		return Box::new(future::ok(cached))
 	}
 
diff --git a/util/network-devp2p/src/host.rs b/util/network-devp2p/src/host.rs
index 1d843e83a..052e80897 100644
--- a/util/network-devp2p/src/host.rs
+++ b/util/network-devp2p/src/host.rs
@@ -709,7 +709,7 @@ impl Host {
 	}
 
 	fn session_writable(&self, token: StreamToken, io: &IoContext<NetworkIoMessage>) {
-		let session = { self.sessions.read().get(token).cloned() };
+		let session = self.sessions.read().get(token).cloned();
 
 		if let Some(session) = session {
 			let mut s = session.lock();
@@ -731,7 +731,7 @@ impl Host {
 		let mut ready_data: Vec<ProtocolId> = Vec::new();
 		let mut packet_data: Vec<(ProtocolId, PacketId, Vec<u8>)> = Vec::new();
 		let mut kill = false;
-		let session = { self.sessions.read().get(token).cloned() };
+		let session = self.sessions.read().get(token).cloned();
 		let mut ready_id = None;
 		if let Some(session) = session.clone() {
 			{
@@ -1005,14 +1005,14 @@ impl Host {
 	}
 
 	pub fn with_context<F>(&self, protocol: ProtocolId, io: &IoContext<NetworkIoMessage>, action: F) where F: FnOnce(&dyn NetworkContextTrait) {
-		let reserved = { self.reserved_nodes.read() };
+		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: FnOnce(&dyn NetworkContextTrait) -> T {
-		let reserved = { self.reserved_nodes.read() };
+		let reserved = self.reserved_nodes.read();
 
 		let context = NetworkContext::new(io, protocol, None, self.sessions.clone(), &reserved);
 		action(&context)
@@ -1145,7 +1145,7 @@ impl IoHandler<NetworkIoMessage> for Host {
 				io.register_timer(handler_token, *delay).unwrap_or_else(|e| debug!("Error registering timer {}: {:?}", token, e));
 			},
 			NetworkIoMessage::Disconnect(ref peer) => {
-				let session = { self.sessions.read().get(*peer).cloned() };
+				let session = self.sessions.read().get(*peer).cloned();
 				if let Some(session) = session {
 					session.lock().disconnect(io, DisconnectReason::DisconnectRequested);
 				}
@@ -1153,7 +1153,7 @@ impl IoHandler<NetworkIoMessage> for Host {
 				self.kill_connection(*peer, io, false);
 			},
 			NetworkIoMessage::DisablePeer(ref peer) => {
-				let session = { self.sessions.read().get(*peer).cloned() };
+				let session = self.sessions.read().get(*peer).cloned();
 				if let Some(session) = session {
 					session.lock().disconnect(io, DisconnectReason::DisconnectRequested);
 					if let Some(id) = session.lock().id() {
@@ -1174,7 +1174,7 @@ impl IoHandler<NetworkIoMessage> for Host {
 	fn register_stream(&self, stream: StreamToken, reg: Token, event_loop: &mut EventLoop<IoManager<NetworkIoMessage>>) {
 		match stream {
 			FIRST_SESSION ..= LAST_SESSION => {
-				let session = { self.sessions.read().get(stream).cloned() };
+				let session = self.sessions.read().get(stream).cloned();
 				if let Some(session) = session {
 					session.lock().register_socket(reg, event_loop).expect("Error registering socket");
 				}
@@ -1211,7 +1211,7 @@ impl IoHandler<NetworkIoMessage> for Host {
 	fn update_stream(&self, stream: StreamToken, reg: Token, event_loop: &mut EventLoop<IoManager<NetworkIoMessage>>) {
 		match stream {
 			FIRST_SESSION ..= LAST_SESSION => {
-				let connection = { self.sessions.read().get(stream).cloned() };
+				let connection = self.sessions.read().get(stream).cloned();
 				if let Some(connection) = connection {
 					connection.lock().update_socket(reg, event_loop).expect("Error updating socket");
 				}