diff --git a/include/gui/DisplayEventReceiver.h b/include/gui/DisplayEventReceiver.h
index cb9b373..6d1ab5d 100644
--- a/include/gui/DisplayEventReceiver.h
+++ b/include/gui/DisplayEventReceiver.h
@@ -32,9 +32,12 @@
 
 // ----------------------------------------------------------------------------
 
-class BitTube;
 class IDisplayEventConnection;
 
+namespace gui {
+class BitTube;
+} // namespace gui
+
 static inline constexpr uint32_t fourcc(char c1, char c2, char c3, char c4) {
     return static_cast<uint32_t>(c1) << 24 |
         static_cast<uint32_t>(c2) << 16 |
@@ -108,14 +111,14 @@
      * should be destroyed and getEvents() shouldn't be called again.
      */
     ssize_t getEvents(Event* events, size_t count);
-    static ssize_t getEvents(const sp<BitTube>& dataChannel,
+    static ssize_t getEvents(const sp<gui::BitTube>& dataChannel,
             Event* events, size_t count);
 
     /*
      * sendEvents write events to the queue and returns how many events were
      * written.
      */
-    static ssize_t sendEvents(const sp<BitTube>& dataChannel,
+    static ssize_t sendEvents(const sp<gui::BitTube>& dataChannel,
             Event const* events, size_t count);
 
     /*
@@ -134,7 +137,7 @@
 
 private:
     sp<IDisplayEventConnection> mEventConnection;
-    sp<BitTube> mDataChannel;
+    sp<gui::BitTube> mDataChannel;
 };
 
 // ----------------------------------------------------------------------------