diff --git a/Cargo.toml b/Cargo.toml
index 0927d98..75a092b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -52,11 +52,6 @@ server = ["buf_redux", "httparse", "quick-error", "safemem", "twoway"]
 mock = []
 nightly = []
 bench = []
-# Use this to enable SSE4.2 instructions in boundary finding
-# TODO: Benchmark this
-sse4 = ["nightly"]
-# switch uses of `Arc<String>` for `Arc<str>` (`From<String>` impl only stabilized in 1.21)
-use_arc_str = []
 
 [[example]]
 name = "hyper_client"
diff --git a/src/server/field.rs b/src/server/field.rs
index 32222c7..b2e6186 100644
--- a/src/server/field.rs
+++ b/src/server/field.rs
@@ -114,7 +114,7 @@ fn copy_headers<'h, 'b: 'h>(raw: &[Header<'b>], headers: &'h mut [StrHeader<'b>]
 #[derive(Clone, Debug)]
 pub struct FieldHeaders {
     /// The field's name from the form.
-    pub name: ArcStr,
+    pub name: Arc<str>,
 
     /// The filename of this entry, if supplied. This is not guaranteed to match the original file
     /// or even to be a valid filename for the current platform.
diff --git a/src/server/mod.rs b/src/server/mod.rs
index c9900e3..d29df21 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -30,20 +30,6 @@ use self::save::SaveBuilder;
 
 pub use self::save::{Entries, SaveResult, SavedField};
 
-/// Default typedef for shared strings.
-///
-/// Enable the `use_arc_str` feature to use `Arc<str>` instead, which saves an indirection but
-/// cannot be constructed in Rust versions older than 1.21 (the `From<String>` impl was stabilized
-/// in that release).
-#[cfg(not(feature = "use_arc_str"))]
-pub type ArcStr = Arc<String>;
-
-/// Optimized typedef for shared strings, replacing `Arc<String>`.
-///
-/// Enabled with the `use_arc_str` feature.
-#[cfg(feature = "use_arc_str")]
-pub type ArcStr = Arc<str>;
-
 macro_rules! try_opt (
     ($expr:expr) => (
         match $expr {