diff --git a/doc/doxygen.cfg.in b/doc/doxygen.cfg.in
index c94f961e..753a4cb9 100644
--- a/doc/doxygen.cfg.in
+++ b/doc/doxygen.cfg.in
@@ -16,6 +16,7 @@ INPUT            = @top_srcdir@/doc/index.doxygen \
 		   @top_srcdir@/include/conf.h \
 		   @top_srcdir@/include/control.h \
 		   @top_srcdir@/include/pcm.h \
+		   @top_srcdir@/include/pcm_plugin.h \
 		   @top_srcdir@/include/rawmidi.h \
 		   @top_srcdir@/include/ump.h \
 		   @top_srcdir@/include/ump_msg.h \