diff --git a/src/AudioTools/CoreAudio/AudioStreams.h b/src/AudioTools/CoreAudio/AudioStreams.h
index 122c9c8ca..584b688f1 100644
--- a/src/AudioTools/CoreAudio/AudioStreams.h
+++ b/src/AudioTools/CoreAudio/AudioStreams.h
@@ -281,10 +281,16 @@ class MemoryStream : public AudioStream {
     return buffer != nullptr;
   }
 
+  /// Provides access to the data array
   virtual uint8_t* data(){
     return buffer;
   }
 
+  /// update the write_pos (e.g. when we used data() to update the array)
+  virtual void setAvailable(size_t len) {
+    this->write_pos = len;
+  }
+
   /// Callback which is executed when we rewind (in loop mode) to the beginning
   void setRewindCallback(void (*cb)()){
     this->rewind = cb;