diff --git a/src/security/pib/identity.hpp b/src/security/pib/identity.hpp
index 228ef16..7c9f714 100644
--- a/src/security/pib/identity.hpp
+++ b/src/security/pib/identity.hpp
@@ -97,18 +97,12 @@
   const Key&
   getDefaultKey() const;
 
-  /*
+  /**
    * @return True if the identity instance is valid
    */
   explicit
   operator bool() const;
 
-  /**
-   * @return True if the identity instance is invalid
-   */
-  bool
-  operator!() const;
-
 NDN_CXX_PUBLIC_WITH_TESTS_ELSE_PRIVATE: // write operations should be private
   /**
    * @brief Add a @p key of @p keyLen bytes (in PKCS#8 format) with @p keyName.