diff --git a/include/asterisk/pbx.h b/include/asterisk/pbx.h
index e84ec59cfe8639d86e5d250ab33f93dd119970b8..95c510fc8c4b31b9d031cd0314a7138b5ac022d4 100755
--- a/include/asterisk/pbx.h
+++ b/include/asterisk/pbx.h
@@ -26,6 +26,9 @@ extern "C" {
 /* Max length of an application */
 #define AST_MAX_APP	32
 
+/* Special return values from applications to the PBX */
+#define AST_PBX_KEEPALIVE	10		/* Destroy the thread, but don't hang up the channel */
+
 struct ast_context;
 
 /* Register a new context */