diff --git a/blockchain/pool_test.go b/blockchain/pool_test.go
index 790216ac0..82120eaef 100644
--- a/blockchain/pool_test.go
+++ b/blockchain/pool_test.go
@@ -34,8 +34,8 @@ func makePeers(numPeers int, minHeight, maxHeight int64) map[p2p.ID]testPeer {
 func TestBasic(t *testing.T) {
 	start := int64(42)
 	peers := makePeers(10, start+1, 1000)
-	errorsCh := make(chan peerError)
-	requestsCh := make(chan BlockRequest)
+	errorsCh := make(chan peerError, 1000)
+	requestsCh := make(chan BlockRequest, 1000)
 	pool := NewBlockPool(start, requestsCh, errorsCh)
 	pool.SetLogger(log.TestingLogger())
 
@@ -91,8 +91,8 @@ func TestBasic(t *testing.T) {
 func TestTimeout(t *testing.T) {
 	start := int64(42)
 	peers := makePeers(10, start+1, 1000)
-	errorsCh := make(chan peerError)
-	requestsCh := make(chan BlockRequest)
+	errorsCh := make(chan peerError, 1000)
+	requestsCh := make(chan BlockRequest, 1000)
 	pool := NewBlockPool(start, requestsCh, errorsCh)
 	pool.SetLogger(log.TestingLogger())
 	err := pool.Start()
diff --git a/blockchain/reactor.go b/blockchain/reactor.go
index cae55e807..7462580b6 100644
--- a/blockchain/reactor.go
+++ b/blockchain/reactor.go
@@ -76,8 +76,9 @@ func NewBlockchainReactor(state sm.State, blockExec *sm.BlockExecutor, store *Bl
 			store.Height()))
 	}
 
-	requestsCh := make(chan BlockRequest)
-	errorsCh := make(chan peerError)
+	const cap = 1000 // must be bigger than peers count
+	requestsCh := make(chan BlockRequest, cap)
+	errorsCh := make(chan peerError, cap) // so we don't block in #Receive#pool.AddBlock
 	pool := NewBlockPool(
 		store.Height()+1,
 		requestsCh,