diff --git a/session.go b/session.go
index 467c992e..16e89e4b 100644
--- a/session.go
+++ b/session.go
@@ -582,6 +582,10 @@ func (s *session) handleMaxDataFrame(frame *wire.MaxDataFrame) {
 }
 
 func (s *session) handleMaxStreamDataFrame(frame *wire.MaxStreamDataFrame) error {
+	if frame.StreamID == s.version.CryptoStreamID() {
+		s.cryptoStream.UpdateSendWindow(frame.ByteOffset)
+		return nil
+	}
 	str, err := s.streamsMap.GetOrOpenStream(frame.StreamID)
 	if err != nil {
 		return err
diff --git a/session_test.go b/session_test.go
index 52c9ad9c..c588b4f7 100644
--- a/session_test.go
+++ b/session_test.go
@@ -393,6 +393,18 @@ var _ = Describe("Session", func() {
 				sess.connFlowController = connFC
 			})
 
+			It("updates the flow control window of the crypto stream", func() {
+				fc := mocks.NewMockStreamFlowController(mockCtrl)
+				offset := protocol.ByteCount(0x4321)
+				fc.EXPECT().UpdateSendWindow(offset)
+				sess.cryptoStream.(*stream).flowController = fc
+				err := sess.handleMaxStreamDataFrame(&wire.MaxStreamDataFrame{
+					StreamID:   sess.version.CryptoStreamID(),
+					ByteOffset: offset,
+				})
+				Expect(err).ToNot(HaveOccurred())
+			})
+
 			It("updates the flow control window of a stream", func() {
 				offset := protocol.ByteCount(0x1234)
 				str, err := sess.GetOrOpenStream(5)