2 files changed, 2 insertions, 2 deletions
diff --git a/src/libstd/io/buffered.rs b/src/libstd/io/buffered.rs
index 476ee3f71ca..7ede050da6c 100644
--- a/src/libstd/io/buffered.rs
+++ b/src/libstd/io/buffered.rs
@@ -918,7 +918,7 @@ impl<W: Write> Write for LineWriter<W> {
         // some data then we *must* report that we wrote that data, so future
         // errors are ignored. We set our internal `need_flush` flag, though, in
         // case flushing fails and we need to try it first next time.
-        let n = self.inner.write(&buf[..i + 1])?;
+        let n = self.inner.write(&buf[..=i])?;
         self.need_flush = true;
         if self.flush().is_err() || n != i + 1 {
             return Ok(n)
diff --git a/src/libstd/io/mod.rs b/src/libstd/io/mod.rs
index 076524e624a..dc97701d889 100644
--- a/src/libstd/io/mod.rs
+++ b/src/libstd/io/mod.rs
@@ -1261,7 +1261,7 @@ fn read_until<R: BufRead + ?Sized>(r: &mut R, delim: u8, buf: &mut Vec<u8>)
             };
             match memchr::memchr(delim, available) {
                 Some(i) => {
-                    buf.extend_from_slice(&available[..i + 1]);
+                    buf.extend_from_slice(&available[..=i]);
                     (true, i + 1)
                 }
                 None => {