diff --git a/ntex-bytes/CHANGELOG.md b/ntex-bytes/CHANGELOG.md
index a2d5b4c4..01c76ce7 100644
--- a/ntex-bytes/CHANGELOG.md
+++ b/ntex-bytes/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changes
 
+## 0.1.2 (2021-06-27)
+
+* Reserve space for put_slice
+
 ## 0.1.1 (2021-06-27)
 
 * Add `ByteString::as_slice()` method
diff --git a/ntex-bytes/Cargo.toml b/ntex-bytes/Cargo.toml
index 3ff103c6..c778932e 100644
--- a/ntex-bytes/Cargo.toml
+++ b/ntex-bytes/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ntex-bytes"
-version = "0.1.1"
+version = "0.1.2"
 license = "MIT"
 authors = ["Carl Lerche <me@carllerche.com>"]
 description = "Types and traits for working with bytes (bytes crate fork)"
@@ -15,6 +15,8 @@ edition = "2018"
 serde = "1.0"
 bytes = "1.0.1"
 
+backtrace = "*"
+
 [dev-dependencies]
 serde_test = "1.0"
 serde_json = "1.0"
diff --git a/ntex-bytes/src/bytes.rs b/ntex-bytes/src/bytes.rs
index 1236d5c8..42761872 100644
--- a/ntex-bytes/src/bytes.rs
+++ b/ntex-bytes/src/bytes.rs
@@ -1566,7 +1566,6 @@ impl BytesMut {
     /// ```
     #[inline]
     pub fn extend_from_slice(&mut self, extend: &[u8]) {
-        self.reserve(extend.len());
         self.put_slice(extend);
     }
 
@@ -1671,9 +1670,8 @@ impl BufMut for BytesMut {
 
     #[inline]
     fn put_slice(&mut self, src: &[u8]) {
-        assert!(self.remaining_mut() >= src.len());
-
         let len = src.len();
+        self.reserve(len);
 
         unsafe {
             ptr::copy_nonoverlapping(
@@ -1687,11 +1685,13 @@ impl BufMut for BytesMut {
 
     #[inline]
     fn put_u8(&mut self, n: u8) {
+        self.reserve(1);
         self.inner.put_u8(n);
     }
 
     #[inline]
     fn put_i8(&mut self, n: i8) {
+        self.reserve(1);
         self.put_u8(n as u8);
     }
 }