diff --git a/CHANGELOG b/CHANGELOG
index 982cf0e..78e5e4d 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,6 @@
+## v4.1.0
+- Mark `hex_bytes2hex_str_unchecked` as unsafe.
+
 ## v4.0.0
 - Use `is_hex_ascii` to optimize performance.
 - Add benchmark results.
diff --git a/Cargo.lock b/Cargo.lock
index 1875b58..233fa07 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,7 +4,7 @@ version = 3
 
 [[package]]
 name = "array-bytes"
-version = "4.0.0"
+version = "4.1.0"
 dependencies = [
  "criterion",
  "faster-hex",
diff --git a/Cargo.toml b/Cargo.toml
index 44938ca..6b11778 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,7 +18,7 @@ license = "GPL-3.0"
 name = "array-bytes"
 readme = "README.md"
 repository = "https://github.com/hack-ink/array-bytes"
-version = "4.0.0"
+version = "4.1.0"
 
 [badges]
 maintenance = { status = "actively-developed" }
diff --git a/benches/bench.rs b/benches/bench.rs
index f6ba86a..984ca46 100644
--- a/benches/bench.rs
+++ b/benches/bench.rs
@@ -8,9 +8,7 @@ use rustc_hex::{FromHex, ToHex};
 const DATA: &[u8] = include_bytes!("../src/lib.rs");
 
 fn bench_encode(c: &mut Criterion) {
-	c.bench_function("array_bytes::bytes2hex", |b| {
-		b.iter(|| array_bytes::bytes2hex("", DATA))
-	});
+	c.bench_function("array_bytes::bytes2hex", |b| b.iter(|| array_bytes::bytes2hex("", DATA)));
 
 	c.bench_function("hex::encode", |b| b.iter(|| hex::encode(DATA)));
 
diff --git a/fuzz/Cargo.toml b/fuzz/Cargo.toml
index 6031956..bcdcd20 100644
--- a/fuzz/Cargo.toml
+++ b/fuzz/Cargo.toml
@@ -4,11 +4,11 @@ edition  = "2021"
 metadata = { cargo-fuzz = true }
 name     = "array-bytes-fuzz"
 publish  = false
-version  = "4.0.0"
+version  = "4.1.0"
 
 [dependencies]
-array-bytes   = { path = ".." }
-libfuzzer-sys = "0.4"
+array-bytes   = { version = "4.1", path = ".." }
+libfuzzer-sys = { version = "0.4" }
 
 [workspace]
 members = ["."]
diff --git a/src/lib.rs b/src/lib.rs
index ac3e9b7..08700f9 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -235,16 +235,16 @@ pub fn hex_bytes2hex_str(bytes: &[u8]) -> ArrayBytesResult<&str> {
 ///
 /// # Examples
 /// ```
-/// assert_eq!(
-/// 	array_bytes::hex_bytes2hex_str_unchecked(b"0x4c6f7665204a616e6520466f7265766572"),
-/// 	"0x4c6f7665204a616e6520466f7265766572",
-/// );
+/// unsafe {
+/// 	assert_eq!(
+/// 		array_bytes::hex_bytes2hex_str_unchecked(b"0x4c6f7665204a616e6520466f7265766572"),
+/// 		"0x4c6f7665204a616e6520466f7265766572",
+/// 	);
+/// }
 /// ```
-pub fn hex_bytes2hex_str_unchecked(bytes: &[u8]) -> &str {
-	unsafe {
-		#[allow(clippy::transmute_bytes_to_str)]
-		mem::transmute(bytes)
-	}
+pub unsafe fn hex_bytes2hex_str_unchecked(bytes: &[u8]) -> &str {
+	#[allow(clippy::transmute_bytes_to_str)]
+	mem::transmute(bytes)
 }
 
 /// [`Bytes`] to [`Hex`].
@@ -599,5 +599,6 @@ where
 fn is_hex_ascii(byte: &u8) -> bool {
 	// Convert to lowercase.
 	let byte = byte | 0b10_0000;
+
 	matches!(byte, b'0'..=b'9' | b'a'..=b'f')
 }
diff --git a/src/test.rs b/src/test.rs
index 7578222..0c8d11d 100644
--- a/src/test.rs
+++ b/src/test.rs
@@ -105,14 +105,16 @@ fn hex_bytes2hex_str_should_work() {
 
 #[test]
 fn hex_bytes2hex_str_unchecked_should_work() {
-	assert_eq!(
-		hex_bytes2hex_str_unchecked(b"0x4c6f7665204a616e6520466f7265766572"),
-		"0x4c6f7665204a616e6520466f7265766572",
-	);
-	assert_eq!(
-		hex_bytes2hex_str_unchecked(b"4c6f7665204a616e6520466f7265766572"),
-		"4c6f7665204a616e6520466f7265766572",
-	);
+	unsafe {
+		assert_eq!(
+			hex_bytes2hex_str_unchecked(b"0x4c6f7665204a616e6520466f7265766572"),
+			"0x4c6f7665204a616e6520466f7265766572",
+		);
+		assert_eq!(
+			hex_bytes2hex_str_unchecked(b"4c6f7665204a616e6520466f7265766572"),
+			"4c6f7665204a616e6520466f7265766572",
+		);
+	}
 }
 
 #[test]