diff --git a/src/proto.h b/src/proto.h
index e606f08..264cbb9 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -183,6 +183,7 @@
 # ifdef FEAT_SIGNS
 #  include "sign.pro"
 # endif
+# include "sound.pro"
 # include "spell.pro"
 # include "spellfile.pro"
 # include "syntax.pro"