diff --git a/tests/unit/test_child.cpp b/tests/unit/test_child.cpp
index 52074f8f1..ae0deec8a 100644
--- a/tests/unit/test_child.cpp
+++ b/tests/unit/test_child.cpp
@@ -143,7 +143,7 @@ void TestChildIp6Address(void)
 
     //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     printf("Child state after init");
-    memset(&child, 0, sizeof(child));
+    child.Clear();
     VerifyChildIp6Addresses(child, 0, NULL);
     printf(" -- PASS\n");