diff --git a/include/media/MediaPlayerInterface.h b/include/media/MediaPlayerInterface.h
index d4aa233..9a8f4b0 100644
--- a/include/media/MediaPlayerInterface.h
+++ b/include/media/MediaPlayerInterface.h
@@ -87,8 +87,9 @@
         virtual ssize_t     frameSize() const = 0;
         virtual uint32_t    latency() const = 0;
         virtual float       msecsPerFrame() const = 0;
-        virtual status_t    getPosition(uint32_t *position) = 0;
-        virtual int         getSessionId() = 0;
+        virtual status_t    getPosition(uint32_t *position) const = 0;
+        virtual status_t    getFramesWritten(uint32_t *frameswritten) const = 0;
+        virtual int         getSessionId() const = 0;
 
         // If no callback is specified, use the "write" API below to submit
         // audio data.