diff --git a/source/6LoWPAN/ws/ws_empty_functions.c b/source/6LoWPAN/ws/ws_empty_functions.c
index a98559a95a2..27edd70137c 100644
--- a/source/6LoWPAN/ws/ws_empty_functions.c
+++ b/source/6LoWPAN/ws/ws_empty_functions.c
@@ -363,6 +363,12 @@ int ws_management_timing_parameters_validate(
 }
 
 /* ### test api ### */
+int ws_test_version_set(int8_t interface_id, uint8_t version)
+{
+    (void) interface_id;
+    (void) version;
+    return -1;
+}
 int ws_test_pan_size_set(int8_t interface_id, uint16_t pan_size)
 {
     (void) interface_id;