diff --git a/openbsc/tests/channel/Makefile.am b/openbsc/tests/channel/Makefile.am
index 6b7468c..50fadc5 100644
--- a/openbsc/tests/channel/Makefile.am
+++ b/openbsc/tests/channel/Makefile.am
@@ -5,6 +5,7 @@
 
 channel_test_SOURCES = channel_test.c \
 	$(top_srcdir)/src/db.c \
+	$(top_srcdir)/src/gsm_subscriber_base.c \
 	$(top_srcdir)/src/gsm_subscriber.c \
 	$(top_srcdir)/src/debug.c \
 	$(top_srcdir)/src/timer.c \