diff --git a/main/pbx.c b/main/pbx.c
index 3de94174076345d68128f7f663ed5fe84bb2bd79..4216b853a217bebb9f3f003e4008b9620b61b1db 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -4133,8 +4133,9 @@ enum ast_extension_states ast_devstate_to_extenstate(enum ast_device_state devst
 		return AST_EXTENSION_ONHOLD;
 	case AST_DEVICE_BUSY:
 		return AST_EXTENSION_BUSY;
-	case AST_DEVICE_UNAVAILABLE:
 	case AST_DEVICE_UNKNOWN:
+		return AST_EXTENSION_NOT_INUSE;
+	case AST_DEVICE_UNAVAILABLE:
 	case AST_DEVICE_INVALID:
 		return AST_EXTENSION_UNAVAILABLE;
 	case AST_DEVICE_RINGINUSE: