diff --git a/media/libnbaio/AudioStreamOutSink.cpp b/media/libnbaio/AudioStreamOutSink.cpp
index b2de8a2..e4341d7 100644
--- a/media/libnbaio/AudioStreamOutSink.cpp
+++ b/media/libnbaio/AudioStreamOutSink.cpp
@@ -81,6 +81,9 @@
 
 status_t AudioStreamOutSink::getTimestamp(AudioTimestamp& timestamp)
 {
+    if (mStream->get_presentation_position == NULL) {
+        return INVALID_OPERATION;
+    }
     // FIXME position64 won't be needed after AudioTimestamp.mPosition is changed to uint64_t
     uint64_t position64;
     int ok = mStream->get_presentation_position(mStream, &position64, &timestamp.mTime);