diff --git a/src/util.rs b/src/util.rs
index 94f2786..4d56fc2 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -110,7 +110,7 @@ pub unsafe fn ykpiv_util_get_cardid(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -158,7 +158,7 @@ pub unsafe fn ykpiv_util_set_cardid(
         );
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -188,7 +188,7 @@ pub unsafe fn ykpiv_util_get_cccid(state: &mut YubiKey, ccc: *mut CCCID) -> Resu
 
         if res.is_ok() {
             if len != CCC_TMPL.len() {
-                _ykpiv_end_transaction(state);
+                let _ = _ykpiv_end_transaction(state);
                 return Err(ErrorKind::GenericError);
             }
 
@@ -245,7 +245,7 @@ pub unsafe fn ykpiv_util_set_cccid(
         res = _ykpiv_save_object(state, YKPIV_OBJ_CAPABILITY as i32, buf.as_mut_ptr(), len);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -337,7 +337,7 @@ pub unsafe fn ykpiv_util_list_keys(
         p_data = calloc(CB_PAGE, 1) as (*mut u8);
 
         if p_data.is_null() {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::MemoryError);
         }
 
@@ -429,7 +429,7 @@ pub unsafe fn ykpiv_util_list_keys(
         free(p_data as (*mut c_void));
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -476,7 +476,7 @@ pub unsafe fn ykpiv_util_read_cert(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -496,7 +496,7 @@ pub unsafe fn ykpiv_util_write_cert(
         res = _write_certificate(state, slot, data, data_len, certinfo);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -615,7 +615,7 @@ pub unsafe fn ykpiv_util_block_puk(state: &mut YubiKey) -> Result<(), ErrorKind>
                 }
             }
         } else {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return res;
         }
     }
@@ -682,14 +682,14 @@ pub unsafe fn ykpiv_util_read_mscmap(
         );
 
         if res.is_err() {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return res;
         }
 
         ptr = buf.as_mut_ptr();
 
         if cb_buf < CB_OBJ_TAG_MIN {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Ok(());
         }
 
@@ -698,7 +698,7 @@ pub unsafe fn ykpiv_util_read_mscmap(
             ptr = ptr.add(_ykpiv_get_length(ptr, &mut len));
 
             if len > cb_buf - (ptr as isize - buf.as_mut_ptr() as isize) as usize {
-                _ykpiv_end_transaction(state);
+                let _ = _ykpiv_end_transaction(state);
                 return Ok(());
             }
 
@@ -746,14 +746,14 @@ pub unsafe fn ykpiv_util_write_mscmap(
                 res = _ykpiv_save_object(state, YKPIV_OBJ_MSCMAP as i32, ptr::null_mut(), 0);
             }
 
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return res;
         }
 
         let req_len = 1 + _ykpiv_set_length(buf.as_mut_ptr(), data_len) + data_len;
 
         if req_len > _obj_size_max(state) {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::SizeError);
         }
 
@@ -769,7 +769,7 @@ pub unsafe fn ykpiv_util_write_mscmap(
         res = _ykpiv_save_object(state, YKPIV_OBJ_MSCMAP as i32, buf.as_mut_ptr(), offset);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -897,7 +897,7 @@ pub unsafe fn ykpiv_util_read_msroots(
         free(p_data as (*mut c_void));
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -925,14 +925,14 @@ pub unsafe fn ykpiv_util_write_msroots(
                 res = _ykpiv_save_object(state, YKPIV_OBJ_MSROOTS1 as i32, ptr::null_mut(), 0);
             }
 
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return res;
         }
 
         n_objs = (data_len / (cb_obj_max - 4)) + 1;
 
         if n_objs > 5 {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::SizeError);
         }
 
@@ -977,7 +977,7 @@ pub unsafe fn ykpiv_util_write_msroots(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1356,7 +1356,7 @@ pub unsafe fn ykpiv_util_generate_key(
         free(ptr_exp as (*mut c_void));
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1517,7 +1517,7 @@ pub unsafe fn ykpiv_util_get_config(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1562,7 +1562,7 @@ pub unsafe fn ykpiv_util_set_pin_last_changed(state: &mut YubiKey) -> Result<(),
             }
         }
     }
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1645,7 +1645,7 @@ pub unsafe fn ykpiv_util_get_derived_mgm(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1705,7 +1705,7 @@ pub unsafe fn ykpiv_util_get_protected_mgm(
     }
 
     data.zeroize();
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1917,7 +1917,7 @@ pub unsafe fn ykpiv_util_set_protected_mgm(
 
     data.zeroize();
     mgm_key.zeroize();
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
 
     res
 }
diff --git a/src/yubikey.rs b/src/yubikey.rs
index 25a1ef2..7587121 100644
--- a/src/yubikey.rs
+++ b/src/yubikey.rs
@@ -491,7 +491,7 @@ pub unsafe fn ykpiv_connect(state: &mut YubiKey, wanted: *const c_char) -> Resul
     _ykpiv_begin_transaction(state)?;
 
     let res = _ykpiv_select_application(state);
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -782,7 +782,7 @@ pub unsafe fn ykpiv_transfer_data(
     }
 
     let res = _ykpiv_transfer_data(state, templ, in_data, in_len, out_data, out_len, sw);
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -878,7 +878,7 @@ pub unsafe fn ykpiv_authenticate(state: &mut YubiKey, mut key: *const u8) -> Res
                 mgm_key.is_null(),
                 "didn't expect mgm key to be set by failing op!"
             );
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::AlgorithmError);
         }
 
@@ -895,12 +895,12 @@ pub unsafe fn ykpiv_authenticate(state: &mut YubiKey, mut key: *const u8) -> Res
         res = _send_data(state, &mut apdu, data.as_mut_ptr(), &mut recv_len, &mut sw);
 
         if res.is_err() {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return res;
         }
 
         if sw != SW_SUCCESS {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::AuthenticationError);
         }
 
@@ -923,7 +923,7 @@ pub unsafe fn ykpiv_authenticate(state: &mut YubiKey, mut key: *const u8) -> Res
         );
 
         if drc != DesErrorKind::Ok {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::AuthenticationError);
         }
 
@@ -949,7 +949,7 @@ pub unsafe fn ykpiv_authenticate(state: &mut YubiKey, mut key: *const u8) -> Res
                 eprintln!("Failed getting randomness for authentication.");
             }
 
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::RandomnessError);
         }
 
@@ -963,12 +963,12 @@ pub unsafe fn ykpiv_authenticate(state: &mut YubiKey, mut key: *const u8) -> Res
         res = _send_data(state, &mut apdu, data.as_mut_ptr(), &mut recv_len, &mut sw);
 
         if res.is_err() {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return res;
         }
 
         if sw != SW_SUCCESS {
-            _ykpiv_end_transaction(state);
+            let _ = _ykpiv_end_transaction(state);
             return Err(ErrorKind::AuthenticationError);
         }
 
@@ -1001,7 +1001,7 @@ pub unsafe fn ykpiv_authenticate(state: &mut YubiKey, mut key: *const u8) -> Res
         des_destroy_key(mgm_key);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1040,7 +1040,7 @@ pub(crate) unsafe fn ykpiv_set_mgmkey2(
                 0 => 0xff,
                 1 => 0xfe,
                 _ => {
-                    _ykpiv_end_transaction(state);
+                    let _ = _ykpiv_end_transaction(state);
                     return Err(ErrorKind::GenericError);
                 }
             };
@@ -1065,7 +1065,7 @@ pub(crate) unsafe fn ykpiv_set_mgmkey2(
     }
 
     apdu.zeroize();
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1220,7 +1220,7 @@ pub unsafe fn ykpiv_sign_data(
         state, raw_in, in_len, sign_out, out_len, algorithm, key, false,
     );
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1239,7 +1239,7 @@ pub unsafe fn ykpiv_decrypt_data(
     // don't attempt to reselect in crypt operations to avoid problems with PIN_ALWAYS
 
     let res = _general_authenticate(state, input, input_len, out, out_len, algorithm, key, true);
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1285,7 +1285,7 @@ pub unsafe fn ykpiv_get_version(state: &mut YubiKey) -> Result<String, ErrorKind
         res = _ykpiv_get_version(state);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res.map(|ver| format!("{}.{}.{}", ver.major, ver.minor, ver.patch))
 }
 
@@ -1426,7 +1426,7 @@ pub unsafe fn ykpiv_get_serial(state: &mut YubiKey) -> Result<u32, ErrorKind> {
         res = _ykpiv_get_serial(state, false);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1563,7 +1563,7 @@ pub unsafe fn ykpiv_verify_select(
         res = _verify(state, pin, pin_len);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1630,7 +1630,7 @@ pub unsafe fn ykpiv_set_pin_retries(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1744,7 +1744,7 @@ pub unsafe fn ykpiv_change_pin(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1770,7 +1770,7 @@ pub unsafe fn ykpiv_change_puk(
         res = _ykpiv_change_pin(state, 2, current_puk, current_puk_len, new_puk, new_puk_len);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1791,7 +1791,7 @@ pub unsafe fn ykpiv_unblock_pin(
         res = _ykpiv_change_pin(state, 1, puk, puk_len, new_pin, new_pin_len);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1810,7 +1810,7 @@ pub unsafe fn ykpiv_fetch_object(
         res = _ykpiv_fetch_object(state, object_id, data, len);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -1894,7 +1894,7 @@ pub unsafe fn ykpiv_save_object(
         res = _ykpiv_save_object(state, object_id, indata, len);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -2135,7 +2135,7 @@ pub unsafe fn ykpiv_import_private_key(
     }
 
     key_data.zeroize();
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -2184,7 +2184,7 @@ pub unsafe fn ykpiv_attest(
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -2219,7 +2219,7 @@ pub unsafe fn ykpiv_auth_getchallenge(state: &mut YubiKey) -> Result<[u8; 8], Er
         }
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -2253,7 +2253,7 @@ pub unsafe fn ykpiv_auth_verifyresponse(
     }
 
     apdu.zeroize();
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }
 
@@ -2292,6 +2292,6 @@ pub unsafe fn ykpiv_auth_deauthenticate(state: &mut YubiKey) -> Result<(), Error
         res = Err(ErrorKind::GenericError);
     }
 
-    _ykpiv_end_transaction(state);
+    let _ = _ykpiv_end_transaction(state);
     res
 }