diff --git a/Makefile.am b/Makefile.am
index fc735d7ef..18cd535ba 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1038,6 +1038,7 @@ libsong_a_SOURCES = \
 	src/song/ModifiedSinceSongFilter.cxx src/song/ModifiedSinceSongFilter.hxx \
 	src/song/AudioFormatSongFilter.cxx src/song/AudioFormatSongFilter.hxx \
 	src/song/AndSongFilter.cxx src/song/AndSongFilter.hxx \
+	src/song/NotSongFilter.hxx \
 	src/song/Filter.cxx src/song/Filter.hxx \
 	src/song/LightSong.cxx src/song/LightSong.hxx