diff --git a/Cargo.lock b/Cargo.lock
index e87e1f3..15c8473 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -703,6 +703,7 @@ dependencies = [
  "ctor",
  "fancy-regex",
  "libc",
+ "memchr",
  "memmap2",
  "phf",
  "phf_codegen",
@@ -896,6 +897,7 @@ version = "0.0.1"
 dependencies = [
  "clap",
  "fancy-regex",
+ "memchr",
  "memmap2",
  "regex",
  "tempfile",
diff --git a/Cargo.toml b/Cargo.toml
index 871f72c..61a7d8c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -38,6 +38,7 @@ clap_complete = "4.5"
 clap_mangen = "0.2"
 fancy-regex = "0.14.0"
 libc = "0.2.153"
+memchr = "2.7.4"
 memmap2 = "0.9"
 phf = "0.11.2"
 phf_codegen = "0.11.2"
@@ -56,6 +57,7 @@ clap_complete = { workspace = true }
 clap_mangen = { workspace = true }
 ctor = "0.4.1"
 fancy-regex =  { workspace = true }
+memchr = { workspace = true }
 memmap2.workspace = true
 phf = { workspace = true }
 sed = { optional = true, version = "0.0.1", package = "uu_sed", path = "src/uu/sed" }
diff --git a/src/uu/sed/Cargo.toml b/src/uu/sed/Cargo.toml
index 6d94616..8487ab2 100644
--- a/src/uu/sed/Cargo.toml
+++ b/src/uu/sed/Cargo.toml
@@ -15,6 +15,7 @@ categories = ["command-line-utilities"]
 [dependencies]
 clap = { workspace = true }
 fancy-regex =  { workspace = true }
+memchr = { workspace = true }
 regex = { workspace = true }
 tempfile = { workspace = true }
 memmap2 = { workspace = true }
diff --git a/src/uu/sed/src/fast_io.rs b/src/uu/sed/src/fast_io.rs
index 36bb53e..1cc7e12 100644
--- a/src/uu/sed/src/fast_io.rs
+++ b/src/uu/sed/src/fast_io.rs
@@ -14,6 +14,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
+use memchr::memchr;
 #[cfg(unix)]
 use memmap2::Mmap;
 
@@ -69,10 +70,12 @@ impl<'a> MmapLineCursor<'a> {
         }
 
         let start = self.pos;
-        let mut end = start;
-        while end < self.data.len() && self.data[end] != b'\n' {
-            end += 1;
-        }
+
+        let mut end = if let Some(pos) = memchr(b'\n', &self.data[start..]) {
+            pos + start
+        } else {
+            self.data.len()
+        };
 
         if end < self.data.len() {
             end += 1; // include \n in full span