diff --git a/openpgp-card/src/card_app.rs b/openpgp-card/src/card_app.rs
index bea83b7..f2b4295 100644
--- a/openpgp-card/src/card_app.rs
+++ b/openpgp-card/src/card_app.rs
@@ -522,7 +522,7 @@ impl CardApp {
 
     /// Run signing operation on the smartcard (low level operation)
     /// (7.2.13 INTERNAL AUTHENTICATE)
-    fn internal_authenticate(
+    pub fn internal_authenticate(
         &mut self,
         data: Vec<u8>,
     ) -> Result<Vec<u8>, Error> {