diff --git a/stepmania/src/Makefile.am b/stepmania/src/Makefile.am
index 5a718c5c9c..d4d10856f4 100644
--- a/stepmania/src/Makefile.am
+++ b/stepmania/src/Makefile.am
@@ -110,6 +110,7 @@ LuaReference.cpp LuaReference.h \
 LuaExpressionTransform.cpp LuaExpressionTransform.h \
 LyricsLoader.cpp LyricsLoader.h \
 MenuInput.cpp MenuInput.h \
+ModsGroup.cpp ModsGroup.h \
 NoteData.cpp NoteData.h NoteDataUtil.cpp NoteDataUtil.h NoteDataWithScoring.cpp NoteDataWithScoring.h \
 NoteTypes.cpp NoteTypes.h NotesLoader.cpp NotesLoader.h \
 NotesLoaderBMS.cpp NotesLoaderBMS.h NotesLoaderDWI.cpp NotesLoaderDWI.h NotesLoaderKSF.cpp NotesLoaderKSF.h \