diff --git a/http/CHANGES.md b/http/CHANGES.md
index e578793f..664f5660 100644
--- a/http/CHANGES.md
+++ b/http/CHANGES.md
@@ -1,4 +1,6 @@
-# unreleased
+# unreleased 0.4.0
+## Change
+- `body::Either` doesn't expose it's enum variants in public API anymore.
 
 # 0.3.0
 ## Add
diff --git a/http/Cargo.toml b/http/Cargo.toml
index 94cf190e..b5b4ac58 100644
--- a/http/Cargo.toml
+++ b/http/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "xitca-http"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 license = "Apache-2.0"
 description = "http library for xitca"
diff --git a/http/src/body.rs b/http/src/body.rs
index 776c7de8..69cab77d 100644
--- a/http/src/body.rs
+++ b/http/src/body.rs
@@ -166,18 +166,25 @@ where
         Poll::Ready(mem::replace(self.get_mut(), Self(None)).0.map(Ok))
     }
 
-    // use the length of buffer as both lower bound and upperbound.
+    // use the length of buffer as both lower bound and upper bound.
     fn size_hint(&self) -> (usize, Option<usize>) {
-        match self.0 {
-            Some(ref b) => exact_body_hint(b.remaining()),
-            None => unreachable!("Once must check size_hint before it got polled"),
-        }
+        self.0
+            .as_ref()
+            .map(|b| exact_body_hint(b.remaining()))
+            .expect("Once must check size_hint before it got polled")
+    }
+}
+
+pin_project! {
+    pub struct Either<L, R> {
+        #[pin]
+        inner: EitherInner<L, R>
     }
 }
 
 pin_project! {
     #[project = EitherProj]
-    pub enum Either<L, R> {
+    enum EitherInner<L, R> {
         L {
             #[pin]
             inner: L
@@ -192,12 +199,16 @@ pin_project! {
 impl<L, R> Either<L, R> {
     #[inline]
     pub const fn left(inner: L) -> Self {
-        Self::L { inner }
+        Self {
+            inner: EitherInner::L { inner },
+        }
     }
 
     #[inline]
     pub const fn right(inner: R) -> Self {
-        Self::R { inner }
+        Self {
+            inner: EitherInner::R { inner },
+        }
     }
 }
 
@@ -211,7 +222,7 @@ where
 
     #[inline]
     fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        match self.project() {
+        match self.project().inner.project() {
             EitherProj::L { inner } => inner.poll_next(cx).map(|res| res.map(|res| res.map_err(Into::into))),
             EitherProj::R { inner } => inner.poll_next(cx),
         }
@@ -219,9 +230,9 @@ where
 
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
-        match *self {
-            Self::L { ref inner } => inner.size_hint(),
-            Self::R { ref inner } => inner.size_hint(),
+        match self.inner {
+            EitherInner::L { ref inner } => inner.size_hint(),
+            EitherInner::R { ref inner } => inner.size_hint(),
         }
     }
 }
diff --git a/web/CHANGES.md b/web/CHANGES.md
index bb7fed8b..3c198708 100644
--- a/web/CHANGES.md
+++ b/web/CHANGES.md
@@ -1,4 +1,6 @@
-# unreleased
+# unreleased 0.4.0
+## Change
+- update `xitca-http` to `0.4.0`
 
 # 0.3.0
 ## Add
diff --git a/web/Cargo.toml b/web/Cargo.toml
index f180b5bc..149000dd 100644
--- a/web/Cargo.toml
+++ b/web/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "xitca-web"
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 license = "Apache-2.0"
 description = "an async web framework"
@@ -76,7 +76,7 @@ serde = ["dep:serde"]
 __server = ["xitca-http/runtime", "xitca-server"]
 
 [dependencies]
-xitca-http = { version = "0.3.0", features = ["router"], default-features = false }
+xitca-http = { version = "0.4.0", features = ["router"], default-features = false }
 xitca-service = { version = "0.1", features = ["alloc", "std"] }
 xitca-unsafe-collection = "0.1"