diff --git a/pjsip/include/pjsua-lib/pjsua.h b/pjsip/include/pjsua-lib/pjsua.h
index 0b42104..b560fca 100644
--- a/pjsip/include/pjsua-lib/pjsua.h
+++ b/pjsip/include/pjsua-lib/pjsua.h
@@ -1744,6 +1744,16 @@
 
 
 /**
+ * This macro specifies the URI scheme to use in Contact header
+ * when secure transport such as TLS is used. Application can specify
+ * either "sip" or "sips".
+ */
+#ifndef PJSUA_SECURE_SCHEME
+#   define PJSUA_SECURE_SCHEME		"sips"
+#endif
+
+
+/**
  * This structure describes account configuration to be specified when
  * adding a new account with #pjsua_acc_add(). Application MUST initialize
  * this structure first by calling #pjsua_acc_config_default().