diff --git a/Makefile.am b/Makefile.am
index 3f52ee5..7a9175f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,4 @@
 AUTOMAKE_OPTIONS = foreign
-SUBDIRS = lib gtfalign gtfcuff gtfformat gtfquant gtfsimulator
+SUBDIRS = lib gtfalign gtfcuff gtfformat gtfquant gtfsimulator gtfmerge
 
 EXTRA_DIST = LICENSE README.md