diff --git a/src/audio/types.h b/src/audio/types.h
index 2e19a5311..7ed530729 100644
--- a/src/audio/types.h
+++ b/src/audio/types.h
@@ -128,7 +128,7 @@ private:
         size_t resample_ch_count;
         int resample_to;
 
-        friend class audio_frame2;
+        friend struct audio_frame2;
 };
 
 /**