diff --git a/ethcore/light/src/on_demand/mod.rs b/ethcore/light/src/on_demand/mod.rs
index fc3d4d30e..4a99c4a39 100644
--- a/ethcore/light/src/on_demand/mod.rs
+++ b/ethcore/light/src/on_demand/mod.rs
@@ -48,7 +48,7 @@ pub struct Account {
 }
 
 /// Errors which can occur while trying to fulfill a request.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub enum Error {
 	/// Request was canceled.
 	Canceled,
@@ -105,6 +105,15 @@ pub struct OnDemand {
 	pending_requests: RwLock<HashMap<ReqId, Pending>>,
 }
 
+impl Default for OnDemand {
+	fn default() -> Self {
+		OnDemand {
+			peers: RwLock::new(HashMap::new()),
+			pending_requests: RwLock::new(HashMap::new()),
+		}
+	}
+}
+
 impl OnDemand {
 	/// Request a header by block number and CHT root hash.
 	pub fn header_by_number(&self, ctx: &BasicContext, req: request::HeaderByNumber) -> Response<encoded::Header> {
@@ -491,3 +500,35 @@ impl Handler for OnDemand {
 		}
 	}
 }
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use on_demand::request;
+	use net::{BasicContext, ReqId, Error as LesError};
+	use request::{Request as LesRequest, Kind as LesRequestKind};
+	use network::{PeerId, NodeId};
+	use futures::Future;
+	use util::H256;
+
+	struct FakeContext;
+
+	impl BasicContext for FakeContext {
+		fn persistent_peer_id(&self, _: PeerId) -> Option<NodeId> { None }
+		fn request_from(&self, _: PeerId, _: LesRequest) -> Result<ReqId, LesError> {
+			unimplemented!()
+		}
+		fn make_announcement(&self, _: Announcement) { }
+		fn max_requests(&self, _: PeerId, _: LesRequestKind) -> usize { 0 }
+		fn disconnect_peer(&self, _: PeerId) { }
+		fn disable_peer(&self, _: PeerId) { }
+	}
+
+	#[test]
+	fn no_peers() {
+		let on_demand = OnDemand::default();
+		let result = on_demand.header_by_hash(&FakeContext, request::HeaderByHash(H256::default()));
+
+		assert_eq!(result.wait().unwrap_err(), Error::NoPeersAvailable);
+	}
+}