reader.go             |  4 ++++
 test/issue377_test.go | 24 +++++++++++++++++++++++-
 torrent.go            |  3 +++

diff --git a/reader.go b/reader.go
index 1f68fdbe6c94e658acbc44a5a37048748e47ddf4..1e1c36e120eaa8df583869cd3ed2a0898998fbd3 100644
--- a/reader.go
+++ b/reader.go
@@ -199,6 +199,10 @@ 		if *ctxErr != nil {
 			err = *ctxErr
 			return
 		}
+		if r.t.dataDownloadDisallowed || !r.t.networkingEnabled {
+			err = errors.New("downloading disabled and data not already available")
+			return
+		}
 		if !wait {
 			return
 		}
diff --git a/test/issue377_test.go b/test/issue377_test.go
index abc57a9051b1841534ff213b19bc5ff11af12fc5..05ef14292c3d75c8afa91ea0b31d642943de4a5b 100644
--- a/test/issue377_test.go
+++ b/test/issue377_test.go
@@ -2,6 +2,8 @@ package test
 
 import (
 	"errors"
+	"io"
+	"io/ioutil"
 	"os"
 	"sync"
 	"testing"
@@ -73,7 +75,27 @@ 	require.NoError(t, err)
 	// Tell the seeder to find the leecher. Is it guaranteed seeders will always try to do this?
 	seederTorrent.AddClientPeer(leecherClient)
 	<-leecherTorrent.GotInfo()
-	assertReadAllGreeting(t, leecherTorrent.NewReader())
+	r := leecherTorrent.Files()[0].NewReader()
+	defer r.Close()
+	// We can't use assertReadAllGreeting here, because the default storage write error handler
+	// disables data downloads, which now causes Readers to error when they're blocked.
+	if false {
+		assertReadAllGreeting(t, leecherTorrent.NewReader())
+	} else {
+		for func() bool {
+			// We don't seem to need to seek, but that's probably just because the storage failure is
+			// happening on the first read.
+			r.Seek(0, io.SeekStart)
+			output, err := ioutil.ReadAll(r)
+			if err != nil {
+				t.Logf("got error while reading: %v", err)
+				return true
+			}
+			assert.EqualValues(t, testutil.GreetingFileContents, output)
+			return false
+		}() {
+		}
+	}
 	// TODO: Check that PeerConns fastEnabled matches seederFast?
 	//select {}
 }
diff --git a/torrent.go b/torrent.go
index ace386eb3fce410cde0a57bf9742fea57e21ee0e..561d3d60bbd9ef265af1f748d19f6b5ca1a9dd24 100644
--- a/torrent.go
+++ b/torrent.go
@@ -2024,6 +2024,7 @@ 	if t.userOnWriteChunkErr != nil {
 		go t.userOnWriteChunkErr(err)
 		return
 	}
+	t.logger.WithDefaultLevel(log.Critical).Printf("default chunk write error handler: disabling data download")
 	t.disallowDataDownloadLocked()
 }
 
@@ -2038,12 +2039,14 @@ 	t.dataDownloadDisallowed = true
 	t.iterPeers(func(c *peer) {
 		c.updateRequests()
 	})
+	t.tickleReaders()
 }
 
 func (t *Torrent) AllowDataDownload() {
 	t.cl.lock()
 	defer t.cl.unlock()
 	t.dataDownloadDisallowed = false
+	t.tickleReaders()
 	t.iterPeers(func(c *peer) {
 		c.updateRequests()
 	})