diff --git a/Cargo.toml b/Cargo.toml
index 0beb3d5308..24dbc8c66b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,6 +27,7 @@ cast_possible_wrap = "allow" # TODO review occurrences
 cast_precision_loss = "allow" # TODO review occurrences
 cast_ptr_alignment = "allow" # TODO review occurrences
 cast_sign_loss = "allow" # TODO review occurrences
+ignored_unit_patterns = "deny"
 missing_errors_doc = "allow" # TODO review occurrences
 missing_panics_doc = "allow" # TODO review occurrences
 missing_safety_doc = "allow" # TODO review occurrences
diff --git a/src/header/dirent/mod.rs b/src/header/dirent/mod.rs
index de3e1f53f8..25c76e9d91 100644
--- a/src/header/dirent/mod.rs
+++ b/src/header/dirent/mod.rs
@@ -140,7 +140,7 @@ impl DIR {
         Ok(dent_ptr)
     }
     fn seek(&mut self, off: u64) {
-        let Ok(_) = Sys::dir_seek(*self.file, off) else {
+        let Ok(()) = Sys::dir_seek(*self.file, off) else {
             return;
         };
         self.buf.clear();
@@ -149,7 +149,7 @@ impl DIR {
     }
     fn rewind(&mut self) {
         self.opaque_offset = 0;
-        let Ok(_) = Sys::dir_seek(*self.file, 0) else {
+        let Ok(()) = Sys::dir_seek(*self.file, 0) else {
             return;
         };
         self.buf.clear();
diff --git a/src/header/poll/mod.rs b/src/header/poll/mod.rs
index 83dac36306..7de0ba5a5b 100644
--- a/src/header/poll/mod.rs
+++ b/src/header/poll/mod.rs
@@ -112,7 +112,7 @@ pub unsafe fn poll_epoll(fds: &mut [pollfd], timeout: c_int, sigmask: *const sig
         }
 
         match unsafe { Sys::epoll_ctl(*ep, EPOLL_CTL_ADD, pfd.fd, &raw mut event) } {
-            Ok(_) => {}
+            Ok(()) => {}
             Err(Errno(EBADF)) => {
                 pfd.revents |= POLLNVAL;
                 closed += 1;
diff --git a/src/header/semaphore/mod.rs b/src/header/semaphore/mod.rs
index b38d3cf5d4..c8ed7f5365 100644
--- a/src/header/semaphore/mod.rs
+++ b/src/header/semaphore/mod.rs
@@ -93,7 +93,7 @@ pub unsafe extern "C" fn sem_unlink(name: *const c_char) -> c_int {
 pub unsafe extern "C" fn sem_wait(sem: *mut sem_t) -> c_int {
     unsafe { get(sem) }
         .wait(None, time::CLOCK_MONOTONIC)
-        .map(|_| 0)
+        .map(|()| 0)
         .or_minus_one_errno()
 }
 
@@ -106,7 +106,7 @@ pub unsafe extern "C" fn sem_clockwait(
 ) -> c_int {
     unsafe { get(sem) }
         .wait(Some(&unsafe { (*abstime).clone() }), clock_id)
-        .map(|_| 0)
+        .map(|()| 0)
         .or_minus_one_errno()
 }
 
@@ -115,7 +115,7 @@ pub unsafe extern "C" fn sem_clockwait(
 pub unsafe extern "C" fn sem_timedwait(sem: *mut sem_t, abstime: *const timespec) -> c_int {
     unsafe { get(sem) }
         .wait(Some(&unsafe { (*abstime).clone() }), time::CLOCK_REALTIME)
-        .map(|_| 0)
+        .map(|()| 0)
         .or_minus_one_errno()
 }
 
diff --git a/src/header/stdio/mod.rs b/src/header/stdio/mod.rs
index 93e717c827..0a3442a929 100644
--- a/src/header/stdio/mod.rs
+++ b/src/header/stdio/mod.rs
@@ -206,15 +206,13 @@ impl Write for FILE {
 
 impl WriteFmt for FILE {
     fn write_str(&mut self, s: &str) -> fmt::Result {
-        self.write_all(s.as_bytes())
-            .map(|_| ())
-            .map_err(|_| fmt::Error)
+        self.write_all(s.as_bytes()).map_err(|_| fmt::Error)
     }
 }
 
 impl WriteByte for FILE {
     fn write_u8(&mut self, c: u8) -> fmt::Result {
-        self.write_all(&[c]).map(|_| ()).map_err(|_| fmt::Error)
+        self.write_all(&[c]).map_err(|_| fmt::Error)
     }
 }
 
diff --git a/src/header/sys_shm/mod.rs b/src/header/sys_shm/mod.rs
index f57543619e..5e30eff7bb 100644
--- a/src/header/sys_shm/mod.rs
+++ b/src/header/sys_shm/mod.rs
@@ -135,7 +135,7 @@ pub unsafe extern "C" fn shmdt(shmaddr: *const c_void) -> c_int {
     let total_size = unsafe { (*header).total_size };
 
     unsafe { Sys::munmap(base_ptr.cast::<c_void>(), total_size) }
-        .map(|_| 0)
+        .map(|()| 0)
         .or_minus_one_errno()
 }
 
@@ -143,7 +143,7 @@ pub unsafe extern "C" fn shmdt(shmaddr: *const c_void) -> c_int {
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn shmctl(shmid: c_int, cmd: c_int, buf: *mut shmid_ds) -> c_int {
     match cmd {
-        IPC_RMID => Sys::close(shmid).map(|_| 0).or_minus_one_errno(),
+        IPC_RMID => Sys::close(shmid).map(|()| 0).or_minus_one_errno(),
         IPC_STAT => {
             if buf.is_null() {
                 ERRNO.set(EINVAL);
diff --git a/src/header/time/mod.rs b/src/header/time/mod.rs
index b4c708042a..0c9636a1cb 100644
--- a/src/header/time/mod.rs
+++ b/src/header/time/mod.rs
@@ -236,7 +236,7 @@ pub unsafe extern "C" fn asctime_r(tm: *const tm, buf: *mut c_char) -> *mut c_ch
         ),
     );
     match write_result {
-        Ok(_) => buf,
+        Ok(()) => buf,
         Err(_) => {
             /* asctime()/asctime_r() or the equivalent sprintf() call
              * have no defined errno setting */
diff --git a/src/io/buffered.rs b/src/io/buffered.rs
index d2d232ab7e..be1cbc83a6 100644
--- a/src/io/buffered.rs
+++ b/src/io/buffered.rs
@@ -505,7 +505,7 @@ impl<W: Write + Seek> Seek for BufWriter<W> {
     ///
     /// Seeking always writes out the internal buffer before seeking.
     fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> {
-        self.flush_buf().and_then(|_| self.get_mut().seek(pos))
+        self.flush_buf().and_then(|()| self.get_mut().seek(pos))
     }
 }