diff --git a/openbsc/include/sccp/sccp.h b/openbsc/include/sccp/sccp.h
index 3ad568c..69ef63c 100644
--- a/openbsc/include/sccp/sccp.h
+++ b/openbsc/include/sccp/sccp.h
@@ -143,4 +143,10 @@
 u_int32_t sccp_src_ref_to_int(struct sccp_source_reference *ref);
 struct sccp_source_reference sccp_src_ref_from_int(u_int32_t);
 
+
+/*
+ * helper functions for the nat code
+ */
+int sccp_determine_msg_type(struct msgb *msg);
+
 #endif