diff --git a/src/cxx/passphrase_callback.hh b/src/cxx/passphrase_callback.hh
index 357b2c6..8482077 100644
--- a/src/cxx/passphrase_callback.hh
+++ b/src/cxx/passphrase_callback.hh
@@ -1,3 +1,5 @@
+#pragma once
+#include <pEp/passphrase_cache.hh>
 
 
 namespace pEp {
@@ -5,5 +7,9 @@ namespace pEp {
 
     char* passphraseRequiredCallback();
 
+        template<typename... A> PEP_STATUS passphraseWrap(
+                PEP_STATUS f(PEP_SESSION, A...), PEP_SESSION session, A... a);
     };
-};
\ No newline at end of file
+};
+
+#include "passphrase_callback.hxx"
\ No newline at end of file
diff --git a/src/passphrase_callback.hxx b/src/cxx/passphrase_callback.hxx
similarity index 100%
rename from src/passphrase_callback.hxx
rename to src/cxx/passphrase_callback.hxx