diff --git a/Makefile.am b/Makefile.am
index 45f216a..39c3c82 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -3,6 +3,9 @@ ACLOCAL_AMFLAGS = -I m4
 include_HEADERS = cudd/cudd.h
 if DDDMP
 include_HEADERS += dddmp/dddmp.h
+include_HEADERS += util/util.h
+include_HEADERS += config.h
+include_HEADERS += mtr/mtr.h
 endif
 if OBJ
 include_HEADERS += cplusplus/cuddObj.hh