diff --git a/examples/tcp_client.rs b/examples/tcp_client.rs
index 413f6b6..d887e57 100644
--- a/examples/tcp_client.rs
+++ b/examples/tcp_client.rs
@@ -6,9 +6,7 @@ use socket2::Type;
 fn main() -> io::Result<()> {
     let socket = socket2::Socket::new(socket2::Domain::IPV4, Type::STREAM, None)?;
     let poller = polling::Poller::new()?;
-    unsafe {
-        poller.add(&socket, Event::new(0, true, true))?;
-    }
+    poller.add(&socket, Event::new(0, true, true))?;
     let addr = net::SocketAddr::new(net::Ipv4Addr::LOCALHOST.into(), 8080);
     socket.set_nonblocking(true)?;
     let _ = socket.connect(&addr.into());
diff --git a/examples/two-listeners.rs b/examples/two-listeners.rs
index bf54eee..510ad84 100644
--- a/examples/two-listeners.rs
+++ b/examples/two-listeners.rs
@@ -10,10 +10,8 @@ fn main() -> io::Result<()> {
     l2.set_nonblocking(true)?;
 
     let poller = Poller::new()?;
-    unsafe {
-        poller.add(&l1, Event::readable(1))?;
-        poller.add(&l2, Event::readable(2))?;
-    }
+    poller.add(&l1, Event::readable(1))?;
+    poller.add(&l2, Event::readable(2))?;
 
     println!("You can connect to the server using `nc`:");
     println!(" $ nc 127.0.0.1 8001");
diff --git a/src/kqueue.rs b/src/kqueue.rs
index 3e0b044..58ae6e2 100644
--- a/src/kqueue.rs
+++ b/src/kqueue.rs
@@ -84,11 +84,17 @@ impl Poller {
     /// # Safety
     ///
     /// The file descriptor must be valid and it must last until it is deleted.
-    pub unsafe fn add(&self, fd: RawFd, ev: Event, mode: PollMode) -> io::Result<()> {
-        self.add_source(SourceId::Fd(fd))?;
+    pub fn add(&self, fd: BorrowedFd<'_>, ev: Event, mode: PollMode) -> io::Result<()> {
+        let rawfd = fd.as_raw_fd();
+
+        // SAFETY: `rawfd` is valid as it is from `BorrowedFd`. And
+        // this block never closes / deletes `rawfd`.
+        unsafe {
+            self.add_source(SourceId::Fd(rawfd))?;
+        }
 
         // File descriptors don't need to be added explicitly, so just modify the interest.
-        self.modify(BorrowedFd::borrow_raw(fd), ev, mode)
+        self.modify(fd, ev, mode)
     }
 
     /// Modifies an existing file descriptor.
diff --git a/src/lib.rs b/src/lib.rs
index 1a2e449..d2ca3d7 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -507,7 +507,7 @@ impl Poller {
     /// poller.delete(&source)?;
     /// # std::io::Result::Ok(())
     /// ```
-    pub unsafe fn add(&self, source: impl AsRawSource, interest: Event) -> io::Result<()> {
+    pub fn add(&self, source: impl AsSource, interest: Event) -> io::Result<()> {
         self.add_with_mode(source, interest, PollMode::Oneshot)
     }
 
@@ -526,9 +526,9 @@ impl Poller {
     ///
     /// If the operating system does not support the specified mode, this function
     /// will return an error.
-    pub unsafe fn add_with_mode(
+    pub fn add_with_mode(
         &self,
-        source: impl AsRawSource,
+        source: impl AsSource,
         interest: Event,
         mode: PollMode,
     ) -> io::Result<()> {
@@ -538,7 +538,7 @@ impl Poller {
                 "the key is not allowed to be `usize::MAX`",
             ));
         }
-        self.poller.add(source.raw(), interest, mode)
+        self.poller.add(source.as_fd(), interest, mode)
     }
 
     /// Modifies the interest in a file descriptor or socket.
diff --git a/tests/concurrent_modification.rs b/tests/concurrent_modification.rs
index ab3e5fb..c4b1965 100644
--- a/tests/concurrent_modification.rs
+++ b/tests/concurrent_modification.rs
@@ -20,9 +20,7 @@ fn concurrent_add() -> io::Result<()> {
         })
         .add(|| {
             thread::sleep(Duration::from_millis(100));
-            unsafe {
-                poller.add(&reader, Event::readable(0))?;
-            }
+            poller.add(&reader, Event::readable(0))?;
             writer.write_all(&[1])?;
             Ok(())
         })
@@ -46,9 +44,7 @@ fn concurrent_add() -> io::Result<()> {
 fn concurrent_modify() -> io::Result<()> {
     let (reader, mut writer) = tcp_pair()?;
     let poller = Poller::new()?;
-    unsafe {
-        poller.add(&reader, Event::none(0))?;
-    }
+    poller.add(&reader, Event::none(0))?;
 
     let mut events = Events::new();
 
@@ -84,9 +80,7 @@ fn concurrent_interruption() -> io::Result<()> {
 
     let (reader, _writer) = tcp_pair()?;
     let poller = Poller::new()?;
-    unsafe {
-        poller.add(&reader, Event::none(0))?;
-    }
+    poller.add(&reader, Event::none(0))?;
 
     let mut events = Events::new();
     let events_borrow = &mut events;
diff --git a/tests/io.rs b/tests/io.rs
index dc42103..70445e9 100644
--- a/tests/io.rs
+++ b/tests/io.rs
@@ -8,9 +8,7 @@ use std::time::Duration;
 fn basic_io() {
     let poller = Poller::new().unwrap();
     let (read, mut write) = tcp_pair().unwrap();
-    unsafe {
-        poller.add(&read, Event::readable(1)).unwrap();
-    }
+    poller.add(&read, Event::readable(1)).unwrap();
 
     // Nothing should be available at first.
     let mut events = Events::new();
@@ -42,7 +40,7 @@ fn basic_io() {
 #[test]
 fn insert_twice() {
     #[cfg(unix)]
-    use std::os::unix::io::AsRawFd;
+    use std::os::unix::io::AsFd;
     #[cfg(windows)]
     use std::os::windows::io::AsRawSocket;
 
@@ -50,18 +48,16 @@ fn insert_twice() {
     let read = Arc::new(read);
 
     let poller = Poller::new().unwrap();
-    unsafe {
-        #[cfg(unix)]
-        let read = read.as_raw_fd();
-        #[cfg(windows)]
-        let read = read.as_raw_socket();
+    #[cfg(unix)]
+    let read = read.as_fd();
+    #[cfg(windows)]
+    let read = read.as_raw_socket();
 
-        poller.add(read, Event::readable(1)).unwrap();
-        assert_eq!(
-            poller.add(read, Event::readable(1)).unwrap_err().kind(),
-            io::ErrorKind::AlreadyExists
-        );
-    }
+    poller.add(read, Event::readable(1)).unwrap();
+    assert_eq!(
+        poller.add(read, Event::readable(1)).unwrap_err().kind(),
+        io::ErrorKind::AlreadyExists
+    );
 
     write.write_all(&[1]).unwrap();
     let mut events = Events::new();
diff --git a/tests/many_connections.rs b/tests/many_connections.rs
index 6a74c9e..3bc3f8c 100644
--- a/tests/many_connections.rs
+++ b/tests/many_connections.rs
@@ -22,9 +22,7 @@ fn many_connections() {
     let poller = polling::Poller::new().unwrap();
 
     for (i, reader, _) in connections.iter() {
-        unsafe {
-            poller.add(reader, polling::Event::readable(*i)).unwrap();
-        }
+        poller.add(reader, polling::Event::readable(*i)).unwrap();
     }
 
     let mut events = Events::new();
diff --git a/tests/multiple_pollers.rs b/tests/multiple_pollers.rs
index 18f0efd..1b84470 100644
--- a/tests/multiple_pollers.rs
+++ b/tests/multiple_pollers.rs
@@ -18,14 +18,12 @@ fn level_triggered() {
 
     // Register the source into both pollers.
     let (mut reader, mut writer) = tcp_pair().unwrap();
-    unsafe {
-        poller1
-            .add_with_mode(&reader, Event::readable(1), PollMode::Level)
-            .unwrap();
-        poller2
-            .add_with_mode(&reader, Event::readable(2), PollMode::Level)
-            .unwrap();
-    }
+    poller1
+        .add_with_mode(&reader, Event::readable(1), PollMode::Level)
+        .unwrap();
+    poller2
+        .add_with_mode(&reader, Event::readable(2), PollMode::Level)
+        .unwrap();
 
     // Neither poller should have any events.
     assert_eq!(
@@ -139,14 +137,12 @@ fn edge_triggered() {
 
     // Register the source into both pollers.
     let (mut reader, mut writer) = tcp_pair().unwrap();
-    unsafe {
-        poller1
-            .add_with_mode(&reader, Event::readable(1), PollMode::Edge)
-            .unwrap();
-        poller2
-            .add_with_mode(&reader, Event::readable(2), PollMode::Edge)
-            .unwrap();
-    }
+    poller1
+        .add_with_mode(&reader, Event::readable(1), PollMode::Edge)
+        .unwrap();
+    poller2
+        .add_with_mode(&reader, Event::readable(2), PollMode::Edge)
+        .unwrap();
 
     // Neither poller should have any events.
     assert_eq!(
@@ -256,14 +252,12 @@ fn oneshot_triggered() {
 
     // Register the source into both pollers.
     let (mut reader, mut writer) = tcp_pair().unwrap();
-    unsafe {
-        poller1
-            .add_with_mode(&reader, Event::readable(1), PollMode::Oneshot)
-            .unwrap();
-        poller2
-            .add_with_mode(&reader, Event::readable(2), PollMode::Oneshot)
-            .unwrap();
-    }
+    poller1
+        .add_with_mode(&reader, Event::readable(1), PollMode::Oneshot)
+        .unwrap();
+    poller2
+        .add_with_mode(&reader, Event::readable(2), PollMode::Oneshot)
+        .unwrap();
 
     // Neither poller should have any events.
     assert_eq!(
diff --git a/tests/other_modes.rs b/tests/other_modes.rs
index 407e42b..bbe3d61 100644
--- a/tests/other_modes.rs
+++ b/tests/other_modes.rs
@@ -16,7 +16,8 @@ fn level_triggered() {
 
     // Create our poller and register our streams.
     let poller = Poller::new().unwrap();
-    if unsafe { poller.add_with_mode(&reader, Event::readable(reader_token), PollMode::Level) }
+    if poller
+        .add_with_mode(&reader, Event::readable(reader_token), PollMode::Level)
         .is_err()
     {
         // Only panic if we're on a platform that should support level mode.
@@ -104,7 +105,8 @@ fn edge_triggered() {
 
     // Create our poller and register our streams.
     let poller = Poller::new().unwrap();
-    if unsafe { poller.add_with_mode(&reader, Event::readable(reader_token), PollMode::Edge) }
+    if poller
+        .add_with_mode(&reader, Event::readable(reader_token), PollMode::Edge)
         .is_err()
     {
         // Only panic if we're on a platform that should support level mode.
@@ -194,14 +196,13 @@ fn edge_oneshot_triggered() {
 
     // Create our poller and register our streams.
     let poller = Poller::new().unwrap();
-    if unsafe {
-        poller.add_with_mode(
+    if poller
+        .add_with_mode(
             &reader,
             Event::readable(reader_token),
             PollMode::EdgeOneshot,
         )
-    }
-    .is_err()
+        .is_err()
     {
         // Only panic if we're on a platform that should support level mode.
         cfg_if::cfg_if! {