diff --git a/bffhd/authentication/fabfire/server.rs b/bffhd/authentication/fabfire/server.rs
index 3108dd8..7a71d7d 100644
--- a/bffhd/authentication/fabfire/server.rs
+++ b/bffhd/authentication/fabfire/server.rs
@@ -495,9 +495,9 @@ impl Authentication for FabFire {
                     Ok(_) => {
                         match apdu_response.body {
                             Some(data) => {
-                                let authid = String::from_utf8(data).unwrap();
+                                let authid = String::from_utf8(data).unwrap().trim_matches(char::from(0)).to_string();
                                 let prov = ThisProvider::<AuthId>::with(
-                                    authid.trim_matches(char::from(0)),
+                                    &authid,
                                 );
                                 let key = session
                                     .need_with::<FabFireCardKey, _, _>(&prov, |key| {
diff --git a/bffhd/authentication/fabfire_bin/server.rs b/bffhd/authentication/fabfire_bin/server.rs
index 5e8cbb1..e9367ab 100644
--- a/bffhd/authentication/fabfire_bin/server.rs
+++ b/bffhd/authentication/fabfire_bin/server.rs
@@ -353,9 +353,9 @@ impl Authentication for FabFire {
                     Ok(_) => {
                         match apdu_response.body {
                             Some(data) => {
-                                let authid = String::from_utf8(data).unwrap();
+                                let authid = String::from_utf8(data).unwrap().trim_matches(char::from(0)).to_string();
                                 let prov = ThisProvider::<AuthId>::with(
-                                    authid.trim_matches(char::from(0)),
+                                    &authid,
                                 );
                                 let key = session
                                     .need_with::<FabFireCardKey, _, _>(&prov, |key| {