diff --git a/Makefile.am b/Makefile.am
index ff49c2a..fd4cd96 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -13,6 +13,7 @@
 	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS)
 
 libpower_la_SOURCES = \
+	gpio.cpp \
 	pmbus.cpp \
 	timer.cpp \
 	utility.cpp \