silent call: add header file for function prototypes
diff --git a/openbsc/src/vty_interface_layer3.c b/openbsc/src/vty_interface_layer3.c
index fe10703..4cc08c2 100644
--- a/openbsc/src/vty_interface_layer3.c
+++ b/openbsc/src/vty_interface_layer3.c
@@ -32,6 +32,7 @@
 #include <openbsc/linuxlist.h>
 #include <openbsc/gsm_data.h>
 #include <openbsc/gsm_subscriber.h>
+#include <openbsc/silent_call.h>
 #include <openbsc/gsm_04_11.h>
 #include <openbsc/e1_input.h>
 #include <openbsc/abis_nm.h>