diff --git a/core/http/Cargo.toml b/core/http/Cargo.toml
index a3537d7b..6c29fa17 100644
--- a/core/http/Cargo.toml
+++ b/core/http/Cargo.toml
@@ -25,7 +25,7 @@ serde = ["uncased/with-serde-alloc", "serde_"]
 uuid = ["uuid_"]
 
 [dependencies]
-smallvec = "1.0"
+smallvec = { version = "1.11", features = ["const_generics", "const_new"] }
 percent-encoding = "2"
 http = "0.2"
 time = { version = "0.3", features = ["formatting", "macros"] }
diff --git a/core/http/src/ext.rs b/core/http/src/ext.rs
index e78012e5..65629c58 100644
--- a/core/http/src/ext.rs
+++ b/core/http/src/ext.rs
@@ -12,12 +12,6 @@ pub trait IntoCollection<T>: Sized {
 
     #[doc(hidden)]
     fn mapped<U, F: FnMut(T) -> U, A: Array<Item=U>>(self, f: F) -> SmallVec<A>;
-
-    #[doc(hidden)]
-    fn mapped_vec<U, F: FnMut(T) -> U>(self, f: F) -> Vec<U> {
-        let small = self.mapped::<U, F, [U; 0]>(f);
-        small.into_vec()
-    }
 }
 
 impl<T> IntoCollection<T> for T {
diff --git a/core/http/src/header/accept.rs b/core/http/src/header/accept.rs
index 305272a6..c38e4932 100644
--- a/core/http/src/header/accept.rs
+++ b/core/http/src/header/accept.rs
@@ -3,7 +3,6 @@ use std::str::FromStr;
 use std::fmt;
 
 use smallvec::SmallVec;
-use either::Either;
 
 use crate::{Header, MediaType};
 use crate::ext::IntoCollection;
@@ -53,30 +52,21 @@ use crate::parse::parse_accept;
 /// let response = Response::build().header(Accept::JSON).finalize();
 /// ```
 #[derive(Debug, Clone)]
-pub struct Accept(pub(crate) AcceptParams);
+pub struct Accept(pub(crate) SmallVec<[QMediaType; 1]>);
 
 /// A `MediaType` with an associated quality value.
 #[derive(Debug, Clone, PartialEq)]
 pub struct QMediaType(pub MediaType, pub Option<f32>);
 
-// NOTE: `Static` is needed for `const` items. Need `const SmallVec::new`.
-#[derive(Debug, Clone)]
-pub enum AcceptParams {
-    Static(QMediaType),
-    Dynamic(SmallVec<[QMediaType; 1]>)
-}
-
 macro_rules! accept_constructor {
     ($($name:ident ($check:ident): $str:expr, $t:expr,
         $s:expr $(; $k:expr => $v:expr)*,)+) => {
         $(
-            #[doc="An `Accept` header with the single media type for <b>"]
-            #[doc=$str] #[doc="</b>: <i>"]
-            #[doc=$t] #[doc="/"] #[doc=$s]
-            #[doc="</i>"]
+            #[doc="An `Accept` header with the single media type for"]
+            #[doc=concat!("**", $str, "**: ", "_", $t, "/", $s, "_")]
             #[allow(non_upper_case_globals)]
             pub const $name: Accept = Accept(
-                AcceptParams::Static(QMediaType(MediaType::$name, None))
+                SmallVec::from_const([QMediaType(MediaType::$name, None)])
             );
          )+
     };
@@ -111,7 +101,7 @@ impl Accept {
     /// ```
     #[inline(always)]
     pub fn new<T: IntoCollection<QMediaType>>(items: T) -> Accept {
-        Accept(AcceptParams::Dynamic(items.into_collection()))
+        Accept(items.into_collection())
     }
 
     // TODO: Implement this.
@@ -211,10 +201,7 @@ impl Accept {
     /// ```
     #[inline(always)]
     pub fn iter(&self) -> impl Iterator<Item=&'_ QMediaType> + '_ {
-        match self.0 {
-            AcceptParams::Static(ref val) => Either::Left(Some(val).into_iter()),
-            AcceptParams::Dynamic(ref vec) => Either::Right(vec.iter())
-        }
+        self.0.iter()
     }
 
     /// Returns an iterator over all of the (bare) media types in `self`. Media
@@ -249,7 +236,7 @@ impl Accept {
 impl<T: IntoCollection<MediaType>> From<T> for Accept {
     #[inline(always)]
     fn from(items: T) -> Accept {
-        Accept(AcceptParams::Dynamic(items.mapped(|item| item.into())))
+        Accept(items.mapped(|item| item.into()))
     }
 }
 
@@ -361,21 +348,6 @@ impl Deref for QMediaType {
     }
 }
 
-impl Default for AcceptParams {
-    fn default() -> Self {
-        AcceptParams::Dynamic(SmallVec::new())
-    }
-}
-
-impl Extend<QMediaType> for AcceptParams {
-    fn extend<T: IntoIterator<Item = QMediaType>>(&mut self, iter: T) {
-        match self {
-            AcceptParams::Static(..) => panic!("can't add to static collection!"),
-            AcceptParams::Dynamic(ref mut v) => v.extend(iter)
-        }
-    }
-}
-
 #[cfg(test)]
 mod test {
     use crate::{Accept, MediaType};
diff --git a/core/http/src/lib.rs b/core/http/src/lib.rs
index bdafb283..7ab89758 100644
--- a/core/http/src/lib.rs
+++ b/core/http/src/lib.rs
@@ -1,5 +1,3 @@
-#![recursion_limit="512"]
-
 #![warn(rust_2018_idioms)]
 #![warn(missing_docs)]