diff --git a/src/security/sec-tpm-osx.hpp b/src/security/sec-tpm-osx.hpp
index fca8dda..fc6360d 100644
--- a/src/security/sec-tpm-osx.hpp
+++ b/src/security/sec-tpm-osx.hpp
@@ -47,14 +47,13 @@
     }
   };
 
-  SecTpmOsx();
+  explicit
+  SecTpmOsx(const std::string& location = "");
 
   virtual
   ~SecTpmOsx();
 
-
   // Following methods are inherited from SecTpm
-
   virtual void
   setTpmPassword(const uint8_t* password, size_t passwordLength);
 
@@ -115,6 +114,9 @@
 
 protected:
   // Following methods are inherited from SecTpm
+  virtual std::string
+  getScheme();
+
   virtual ConstBufferPtr
   exportPrivateKeyPkcs8FromTpm(const Name& keyName)
   {
@@ -150,6 +152,9 @@
                     const Name& keyName, DigestAlgorithm digestAlgorithm,
                     bool needRetry);
 
+public:
+  static const std::string SCHEME;
+
 private:
   class Impl;
   shared_ptr<Impl> m_impl;