diff --git a/gpio-util/Makefile.am b/gpio-util/Makefile.am
index 9bdc42d..241cb19 100644
--- a/gpio-util/Makefile.am
+++ b/gpio-util/Makefile.am
@@ -5,6 +5,7 @@
 	phosphor-gpio-util
 
 phosphor_gpio_util_SOURCES = \
+	argument.cpp \
 	gpio.cpp \
 	main.cpp