diff --git a/remote.go b/remote.go
index 6765e45..59a6014 100644
--- a/remote.go
+++ b/remote.go
@@ -248,6 +248,10 @@ func credentialsCallback(_cred **C.git_cred, _url *C.char, _username_from_url *C
 	ret, cred := callbacks.CredentialsCallback(url, username_from_url, (CredType)(allowed_types))
 	if cred != nil {
 		*_cred = cred.ptr
+
+		// have transferred ownership to libgit, 'forget' the native pointer
+		cred.ptr = nil
+		runtime.SetFinalizer(cred, nil)
 	}
 	return int(ret)
 }