diff --git a/include/telephony/ril.h b/include/telephony/ril.h
index 185f3c0..487830d 100644
--- a/include/telephony/ril.h
+++ b/include/telephony/ril.h
@@ -256,6 +256,7 @@
 
 /* See RIL_REQUEST_LAST_CALL_FAIL_CAUSE */
 typedef enum {
+    CALL_FAIL_UNOBTAINABLE_NUMBER = 1,
     CALL_FAIL_NORMAL = 16,
     CALL_FAIL_BUSY = 17,
     CALL_FAIL_CONGESTION = 34,