diff --git a/Cargo.lock b/Cargo.lock
index 67e7c765..565ed15a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -210,8 +210,7 @@ dependencies = [
 [[package]]
 name = "nitrokey"
 version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ddeb2d19d5499ab4740c0131562e8c4b2c13f8954677be4318c1efc944911531"
+source = "git+https://git.sr.ht/~ireas/nitrokey-rs?branch=backend#16f6c38eff783382cf1f1679271254aa85e7ce1d"
 dependencies = [
  "lazy_static",
  "libc",
diff --git a/Cargo.toml b/Cargo.toml
index 19e77bc9..1b9a149f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,7 +56,8 @@ version = "0.2"
 version = "0.1"
 
 [dependencies.nitrokey]
-version = "0.9.0"
+git = "https://git.sr.ht/~ireas/nitrokey-rs"
+branch = "backend"
 
 [dependencies.progressing]
 version = "3.0.2"
diff --git a/src/commands.rs b/src/commands.rs
index ad61c65d..cbb37854 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -112,7 +112,7 @@ fn find_device(config: &config::Config) -> anyhow::Result<nitrokey::DeviceInfo>
 
 /// Connect to a Nitrokey device that matches the given requirements
 fn connect<'mgr>(
-  manager: &'mgr mut nitrokey::Manager,
+  manager: &'mgr nitrokey::Manager,
   config: &config::Config,
 ) -> anyhow::Result<nitrokey::DeviceWrapper<'mgr>> {
   let device_info = find_device(config)?;
@@ -131,12 +131,11 @@ fn with_device<F>(ctx: &mut Context<'_>, op: F) -> anyhow::Result<()>
 where
   F: FnOnce(&mut Context<'_>, nitrokey::DeviceWrapper<'_>) -> anyhow::Result<()>,
 {
-  let mut manager =
-    nitrokey::take().context("Failed to acquire access to Nitrokey device manager")?;
+  let manager = nitrokey::take().context("Failed to acquire access to Nitrokey device manager")?;
 
   set_log_level(ctx);
 
-  let device = connect(&mut manager, &ctx.config)?;
+  let device = connect(&manager, &ctx.config)?;
   op(ctx, device)
 }
 
@@ -145,8 +144,7 @@ fn with_storage_device<F>(ctx: &mut Context<'_>, op: F) -> anyhow::Result<()>
 where
   F: FnOnce(&mut Context<'_>, nitrokey::Storage<'_>) -> anyhow::Result<()>,
 {
-  let mut manager =
-    nitrokey::take().context("Failed to acquire access to Nitrokey device manager")?;
+  let manager = nitrokey::take().context("Failed to acquire access to Nitrokey device manager")?;
 
   set_log_level(ctx);
 
@@ -158,7 +156,7 @@ where
     ctx.config.model = Some(args::DeviceModel::Storage);
   }
 
-  let device = connect(&mut manager, &ctx.config)?;
+  let device = connect(&manager, &ctx.config)?;
   if let nitrokey::DeviceWrapper::Storage(storage) = device {
     op(ctx, storage)
   } else {
@@ -518,7 +516,7 @@ pub fn list(ctx: &mut Context<'_>, no_connect: bool) -> anyhow::Result<()> {
     println!(ctx, "No Nitrokey device connected")?;
   } else {
     println!(ctx, "USB path\tmodel\tserial number")?;
-    let mut manager =
+    let manager =
       nitrokey::take().context("Failed to acquire access to Nitrokey device manager")?;
 
     for device_info in device_infos {
diff --git a/src/tests/encrypted.rs b/src/tests/encrypted.rs
index 085a5687..a93841d3 100644
--- a/src/tests/encrypted.rs
+++ b/src/tests/encrypted.rs
@@ -66,7 +66,7 @@ fn encrypted_open_close(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_storage()?;
     assert!(device.get_storage_status()?.encrypted_volume.active);
     assert!(!device.get_storage_status()?.hidden_volume.active);
@@ -76,7 +76,7 @@ fn encrypted_open_close(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_storage()?;
     assert!(!device.get_storage_status()?.encrypted_volume.active);
     assert!(!device.get_storage_status()?.hidden_volume.active);
diff --git a/src/tests/hidden.rs b/src/tests/hidden.rs
index 1b072e1c..21ffd8b6 100644
--- a/src/tests/hidden.rs
+++ b/src/tests/hidden.rs
@@ -15,7 +15,7 @@ fn hidden_create_open_close(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_storage()?;
     assert!(!device.get_storage_status()?.encrypted_volume.active);
     assert!(device.get_storage_status()?.hidden_volume.active);
@@ -25,7 +25,7 @@ fn hidden_create_open_close(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_storage()?;
     assert!(!device.get_storage_status()?.encrypted_volume.active);
     assert!(!device.get_storage_status()?.hidden_volume.active);
diff --git a/src/tests/lock.rs b/src/tests/lock.rs
index 51804863..3d66500a 100644
--- a/src/tests/lock.rs
+++ b/src/tests/lock.rs
@@ -22,7 +22,7 @@ fn lock_storage(model: nitrokey::Model) -> anyhow::Result<()> {
   let out = ncli.handle(&["lock"])?;
   assert!(out.is_empty());
 
-  let mut manager = nitrokey::force_take()?;
+  let manager = nitrokey::force_take()?;
   let device = manager.connect_storage()?;
   assert!(!device.get_storage_status()?.encrypted_volume.active);
 
diff --git a/src/tests/pin.rs b/src/tests/pin.rs
index 484e256a..44612885 100644
--- a/src/tests/pin.rs
+++ b/src/tests/pin.rs
@@ -11,7 +11,7 @@ use super::*;
 #[test_device]
 fn unblock(model: nitrokey::Model) -> anyhow::Result<()> {
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_model(model)?;
     let (device, err) = device.authenticate_user("wrong-pin").unwrap_err();
     match err {
@@ -24,7 +24,7 @@ fn unblock(model: nitrokey::Model) -> anyhow::Result<()> {
   let _ = Nitrocli::new().model(model).handle(&["pin", "unblock"])?;
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_model(model)?;
     assert_eq!(device.get_user_retry_count()?, 3);
   }
@@ -40,7 +40,7 @@ fn set_user(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_model(model)?;
     let (_, err) = device
       .authenticate_user(nitrokey::DEFAULT_USER_PIN)
@@ -61,7 +61,7 @@ fn set_user(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_model(model)?;
     let _ = device
       .authenticate_user(nitrokey::DEFAULT_USER_PIN)
diff --git a/src/tests/pws.rs b/src/tests/pws.rs
index 7ad1e314..58b0f998 100644
--- a/src/tests/pws.rs
+++ b/src/tests/pws.rs
@@ -8,7 +8,7 @@ use nitrokey::GetPasswordSafe as _;
 use super::*;
 
 fn clear_pws(model: nitrokey::Model) -> anyhow::Result<()> {
-  let mut manager = nitrokey::force_take()?;
+  let manager = nitrokey::force_take()?;
   let mut device = manager.connect_model(model)?;
   let mut pws = device.get_password_safe(nitrokey::DEFAULT_USER_PIN)?;
   let slots_to_clear = pws
@@ -342,7 +342,7 @@ fn add_full(model: nitrokey::Model) -> anyhow::Result<()> {
 
   // Fill all PWS slots
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let mut device = manager.connect_model(model)?;
     let mut pws = device.get_password_safe(nitrokey::DEFAULT_USER_PIN)?;
     for slot in 0..pws.get_slot_count() {
diff --git a/src/tests/reset.rs b/src/tests/reset.rs
index 78fd13c7..d3dcdfd2 100644
--- a/src/tests/reset.rs
+++ b/src/tests/reset.rs
@@ -17,7 +17,7 @@ fn reset(model: nitrokey::Model) -> anyhow::Result<()> {
   let _ = ncli.handle(&["pin", "set", "admin"])?;
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     // Check that the admin PIN has been changed.
     let device = manager.connect_model(model)?;
     let _ = device.authenticate_admin(new_admin_pin).unwrap();
@@ -29,7 +29,7 @@ fn reset(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     // Check that the admin PIN has been reset.
     let device = manager.connect_model(model)?;
     let mut device = device
@@ -58,7 +58,7 @@ fn reset_only_aes_key(model: nitrokey::Model) -> anyhow::Result<()> {
 
   // Add an entry to the PWS
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let mut device = manager.connect_model(model)?;
     let mut pws = device.get_password_safe(NEW_USER_PIN)?;
     pws.write_slot(0, NAME, LOGIN, PASSWORD)?;
@@ -74,7 +74,7 @@ fn reset_only_aes_key(model: nitrokey::Model) -> anyhow::Result<()> {
   // been replaced, and that 3) the changed user PIN still works, i.e.,
   // we did not perform a factory reset.
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let mut device = manager.connect_model(model)?;
     let pws = device.get_password_safe(NEW_USER_PIN)?;
     let slot = pws.get_slot_unchecked(0)?;
diff --git a/src/tests/unencrypted.rs b/src/tests/unencrypted.rs
index 89049de8..f4516b32 100644
--- a/src/tests/unencrypted.rs
+++ b/src/tests/unencrypted.rs
@@ -12,7 +12,7 @@ fn unencrypted_set_read_write(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_storage()?;
     assert!(device.get_storage_status()?.unencrypted_volume.active);
     assert!(!device.get_storage_status()?.unencrypted_volume.read_only);
@@ -22,7 +22,7 @@ fn unencrypted_set_read_write(model: nitrokey::Model) -> anyhow::Result<()> {
   assert!(out.is_empty());
 
   {
-    let mut manager = nitrokey::force_take()?;
+    let manager = nitrokey::force_take()?;
     let device = manager.connect_storage()?;
     assert!(device.get_storage_status()?.unencrypted_volume.active);
     assert!(device.get_storage_status()?.unencrypted_volume.read_only);