diff --git a/src/core/mac/mac_types.hpp b/src/core/mac/mac_types.hpp
index cd2802e31..6e8ba3792 100644
--- a/src/core/mac/mac_types.hpp
+++ b/src/core/mac/mac_types.hpp
@@ -469,6 +469,8 @@ public:
      *
      */
     KeyMaterial &operator=(const KeyMaterial &aOther);
+
+    KeyMaterial(const KeyMaterial &) = delete;
 #endif
 
     /**
@@ -539,8 +541,6 @@ public:
      */
     bool operator==(const KeyMaterial &aOther) const;
 
-    KeyMaterial(const KeyMaterial &) = delete;
-
 private:
 #if OPENTHREAD_CONFIG_PLATFORM_KEY_REFERENCES_ENABLE
     static constexpr KeyRef kInvalidKeyRef = Crypto::Storage::kInvalidKeyRef;