diff --git a/src/core/thread/child_table.hpp b/src/core/thread/child_table.hpp
index 3a3b3e1e1..479dea932 100644
--- a/src/core/thread/child_table.hpp
+++ b/src/core/thread/child_table.hpp
@@ -308,7 +308,7 @@ public:
      */
     bool Contains(const Neighbor &aNeighbor) const
     {
-        const Child *child = static_cast<const Child *>(&aNeighbor);
+        const void *child = &aNeighbor;
 
         return (mChildren <= child) && (child < GetArrayEnd(mChildren));
     }