diff --git i/eth/downloader/downloader.go w/eth/downloader/downloader.go
index 43f0e3db9..b337f95c9 100644
--- i/eth/downloader/downloader.go
+++ w/eth/downloader/downloader.go
@@ -143,6 +143,8 @@ type Downloader struct {
 	quitCh   chan struct{} // Quit channel to signal termination
 	quitLock sync.RWMutex  // Lock to prevent double closes
 
+	downloads sync.WaitGroup // Keeps track of the currently active downloads
+
 	// Testing hooks
 	syncInitHook     func(uint64, uint64)  // Method to call upon initiating a new sync run
 	bodyFetchHook    func([]*types.Header) // Method to call upon starting a block body fetch
@@ -403,7 +405,9 @@ func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int, mode
 // specified peer and head hash.
 func (d *Downloader) syncWithPeer(p *peerConnection, hash common.Hash, td *big.Int) (err error) {
 	d.mux.Post(StartEvent{})
+	d.downloads.Add(1)
 	defer func() {
+		d.downloads.Done()
 		// reset on error
 		if err != nil {
 			d.mux.Post(FailedEvent{err})
@@ -471,14 +475,22 @@ func (d *Downloader) syncWithPeer(p *peerConnection, hash common.Hash, td *big.I
 	} else if d.mode == FullSync {
 		fetchers = append(fetchers, d.processFullSyncContent)
 	}
-	return d.spawnSync(fetchers)
+	return d.spawnSync(errCancelHeaderFetch, fetchers)
 }
 
 // spawnSync runs d.process and all given fetcher functions to completion in
 // separate goroutines, returning the first error that appears.
-func (d *Downloader) spawnSync(fetchers []func() error) error {
+func (d *Downloader) spawnSync(errCancel error, fetchers []func() error) error {
+	d.cancelLock.Lock()
+	select {
+	case <-d.cancelCh:
+		d.cancelLock.Unlock()
+		return errCancel
+	default:
+	}
 	errc := make(chan error, len(fetchers))
 	d.cancelWg.Add(len(fetchers))
+	d.cancelLock.Unlock()
 	for _, fn := range fetchers {
 		fn := fn
 		go func() { defer d.cancelWg.Done(); errc <- fn() }()
@@ -539,6 +551,10 @@ func (d *Downloader) Terminate() {
 
 	// Cancel any pending download requests
 	d.Cancel()
+
+	// Wait, so external dependencies aren't destroyed
+	// until the download processing is done.
+	d.downloads.Wait()
 }
 
 // fetchHeight retrieves the head header of the remote peer to aid in estimating
diff --git i/eth/handler.go w/eth/handler.go
index 4069359c9..da9ebb243 100644
--- i/eth/handler.go
+++ w/eth/handler.go
@@ -230,6 +230,9 @@ func (pm *ProtocolManager) Stop() {
 	// Quit fetcher, txsyncLoop.
 	close(pm.quitSync)
 
+	// Stop downloader and make sure that all the running downloads are complete.
+	pm.downloader.Terminate()
+
 	// Disconnect existing sessions.
 	// This also closes the gate for any new registrations on the peer set.
 	// sessions which are already established but not added to pm.peers yet
diff --git i/eth/sync.go w/eth/sync.go
index e49e40087..4367434a6 100644
--- i/eth/sync.go
+++ w/eth/sync.go
@@ -135,7 +135,6 @@ func (pm *ProtocolManager) syncer() {
 	// Start and ensure cleanup of sync mechanisms
 	pm.fetcher.Start()
 	defer pm.fetcher.Stop()
-	defer pm.downloader.Terminate()
 
 	// Wait for different events to fire synchronisation operations
 	forceSync := time.NewTicker(forceSyncCycle)
diff --git i/les/backend.go w/les/backend.go
index 6a324cb04..e3844bf84 100644
--- i/les/backend.go
+++ w/les/backend.go
@@ -20,7 +20,6 @@ package les
 import (
 	"fmt"
 	"sync"
-	"time"
 
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
@@ -250,7 +249,6 @@ func (s *LightEthereum) Stop() error {
 
 	s.eventMux.Stop()
 
-	time.Sleep(time.Millisecond * 200)
 	s.chainDb.Close()
 	close(s.shutdownChan)
 
diff --git i/les/handler.go w/les/handler.go
index 9627f392b..f2bbe899f 100644
--- i/les/handler.go
+++ w/les/handler.go
@@ -241,6 +241,9 @@ func (pm *ProtocolManager) Stop() {
 
 	close(pm.quitSync) // quits syncer, fetcher
 
+	// Stop downloader and make sure that all the running downloads are complete.
+	pm.downloader.Terminate()
+
 	// Disconnect existing sessions.
 	// This also closes the gate for any new registrations on the peer set.
 	// sessions which are already established but not added to pm.peers yet
diff --git i/les/sync.go w/les/sync.go
index c3d37e2f3..fc1f076c7 100644
--- i/les/sync.go
+++ w/les/sync.go
@@ -31,7 +31,6 @@ func (pm *ProtocolManager) syncer() {
 	// Start and ensure cleanup of sync mechanisms
 	//pm.fetcher.Start()
 	//defer pm.fetcher.Stop()
-	defer pm.downloader.Terminate()
 
 	// Wait for different events to fire synchronisation operations
 	//forceSync := time.Tick(forceSyncCycle)