diff --git a/Userland/Libraries/LibAudio/Forward.h b/Userland/Libraries/LibAudio/Forward.h
index 72f499f8904..a6ab1189065 100644
--- a/Userland/Libraries/LibAudio/Forward.h
+++ b/Userland/Libraries/LibAudio/Forward.h
@@ -10,6 +10,9 @@ namespace Audio {
 
 class ConnectionToServer;
 class Loader;
+class Encoder;
+struct Person;
+struct Metadata;
 class PlaybackStream;
 struct Sample;