diff --git a/benches/client_mock_tcp.rs b/benches/client_mock_tcp.rs
index eb5760ee90..5caae756e5 100644
--- a/benches/client_mock_tcp.rs
+++ b/benches/client_mock_tcp.rs
@@ -1,4 +1,4 @@
-#![feature(core, collections, io, test)]
+#![feature(collections, io, test)]
 extern crate hyper;
 
 extern crate test;
diff --git a/src/header/common/authorization.rs b/src/header/common/authorization.rs
index adb8e2650e..9999089e4f 100644
--- a/src/header/common/authorization.rs
+++ b/src/header/common/authorization.rs
@@ -32,9 +32,9 @@ impl<S: Scheme> Header for Authorization<S> {
             match (from_utf8(unsafe { &raw[].get_unchecked(0)[] }), Scheme::scheme(None::<S>)) {
                 (Ok(header), Some(scheme))
                     if header.starts_with(scheme) && header.len() > scheme.len() + 1 => {
-                    header[scheme.len() + 1..].parse::<S>().map(|s| Authorization(s))
+                    header[scheme.len() + 1..].parse::<S>().map(|s| Authorization(s)).ok()
                 },
-                (Ok(header), None) => header.parse::<S>().map(|s| Authorization(s)),
+                (Ok(header), None) => header.parse::<S>().map(|s| Authorization(s)).ok(),
                 _ => None
             }
         } else {
@@ -108,32 +108,33 @@ impl Scheme for Basic {
 }
 
 impl FromStr for Basic {
-    fn from_str(s: &str) -> Option<Basic> {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Basic, ()> {
         match s.from_base64() {
             Ok(decoded) => match String::from_utf8(decoded) {
                 Ok(text) => {
                     let mut parts = &mut text[].split(':');
                     let user = match parts.next() {
                         Some(part) => part.to_string(),
-                        None => return None
+                        None => return Err(())
                     };
                     let password = match parts.next() {
                         Some(part) => Some(part.to_string()),
                         None => None
                     };
-                    Some(Basic {
+                    Ok(Basic {
                         username: user,
                         password: password
                     })
                 },
                 Err(e) => {
                     debug!("Basic::from_utf8 error={:?}", e);
-                    None
+                    Err(())
                 }
             },
             Err(e) => {
                 debug!("Basic::from_base64 error={:?}", e);
-                None
+                Err(())
             }
         }
     }
diff --git a/src/header/common/cache_control.rs b/src/header/common/cache_control.rs
index f49ea5ccc9..50e4a4af4c 100644
--- a/src/header/common/cache_control.rs
+++ b/src/header/common/cache_control.rs
@@ -96,28 +96,29 @@ impl fmt::Display for CacheDirective {
 }
 
 impl FromStr for CacheDirective {
-    fn from_str(s: &str) -> Option<CacheDirective> {
+    type Err = Option<<u32 as FromStr>::Err>;
+    fn from_str(s: &str) -> Result<CacheDirective, Option<<u32 as FromStr>::Err>> {
         use self::CacheDirective::*;
         match s {
-            "no-cache" => Some(NoCache),
-            "no-store" => Some(NoStore),
-            "no-transform" => Some(NoTransform),
-            "only-if-cached" => Some(OnlyIfCached),
-            "must-revalidate" => Some(MustRevalidate),
-            "public" => Some(Public),
-            "private" => Some(Private),
-            "proxy-revalidate" => Some(ProxyRevalidate),
-            "" => None,
+            "no-cache" => Ok(NoCache),
+            "no-store" => Ok(NoStore),
+            "no-transform" => Ok(NoTransform),
+            "only-if-cached" => Ok(OnlyIfCached),
+            "must-revalidate" => Ok(MustRevalidate),
+            "public" => Ok(Public),
+            "private" => Ok(Private),
+            "proxy-revalidate" => Ok(ProxyRevalidate),
+            "" => Err(None),
             _ => match s.find('=') {
                 Some(idx) if idx+1 < s.len() => match (&s[..idx], &s[idx+1..].trim_matches('"')) {
-                    ("max-age" , secs) => secs.parse().map(MaxAge),
-                    ("max-stale", secs) => secs.parse().map(MaxStale),
-                    ("min-fresh", secs) => secs.parse().map(MinFresh),
-                    ("s-maxage", secs) => secs.parse().map(SMaxAge),
-                    (left, right) => Some(Extension(left.to_string(), Some(right.to_string())))
+                    ("max-age" , secs) => secs.parse().map(MaxAge).map_err(|x| Some(x)),
+                    ("max-stale", secs) => secs.parse().map(MaxStale).map_err(|x| Some(x)),
+                    ("min-fresh", secs) => secs.parse().map(MinFresh).map_err(|x| Some(x)),
+                    ("s-maxage", secs) => secs.parse().map(SMaxAge).map_err(|x| Some(x)),
+                    (left, right) => Ok(Extension(left.to_string(), Some(right.to_string())))
                 },
-                Some(_) => None,
-                None => Some(Extension(s.to_string(), None))
+                Some(_) => Err(None),
+                None => Ok(Extension(s.to_string(), None))
             }
         }
     }
diff --git a/src/header/common/connection.rs b/src/header/common/connection.rs
index a4735f9335..3c1dd88dd2 100644
--- a/src/header/common/connection.rs
+++ b/src/header/common/connection.rs
@@ -31,11 +31,12 @@ pub enum ConnectionOption {
 }
 
 impl FromStr for ConnectionOption {
-    fn from_str(s: &str) -> Option<ConnectionOption> {
+    type Err = ();
+    fn from_str(s: &str) -> Result<ConnectionOption, ()> {
         match s {
-            "keep-alive" => Some(KeepAlive),
-            "close" => Some(Close),
-            s => Some(ConnectionHeader(UniCase(s.to_string())))
+            "keep-alive" => Ok(KeepAlive),
+            "close" => Ok(Close),
+            s => Ok(ConnectionHeader(UniCase(s.to_string())))
         }
     }
 }
diff --git a/src/header/common/cookie.rs b/src/header/common/cookie.rs
index 6f7c36ab36..fa68ab2d18 100644
--- a/src/header/common/cookie.rs
+++ b/src/header/common/cookie.rs
@@ -30,8 +30,8 @@ impl Header for Cookie {
                 Ok(cookies_str) => {
                     for cookie_str in cookies_str.split(';') {
                         match cookie_str.trim().parse() {
-                            Some(cookie) => cookies.push(cookie),
-                            None => return None
+                            Ok(cookie) => cookies.push(cookie),
+                            Err(_) => return None
                         }
                     }
                 },
diff --git a/src/header/common/date.rs b/src/header/common/date.rs
index 28e7ad5bdf..b9e6d97bad 100644
--- a/src/header/common/date.rs
+++ b/src/header/common/date.rs
@@ -35,8 +35,9 @@ impl HeaderFormat for Date {
 }
 
 impl FromStr for Date {
-    fn from_str(s: &str) -> Option<Date> {
-        tm_from_str(s).map(Date)
+    type Err = ();
+    fn from_str(s: &str) -> Result<Date, ()> {
+        tm_from_str(s).map(Date).ok_or(())
     }
 }
 
diff --git a/src/header/common/expires.rs b/src/header/common/expires.rs
index 7878326da4..8969bfdb94 100644
--- a/src/header/common/expires.rs
+++ b/src/header/common/expires.rs
@@ -34,8 +34,9 @@ impl HeaderFormat for Expires {
 }
 
 impl FromStr for Expires {
-    fn from_str(s: &str) -> Option<Expires> {
-        tm_from_str(s).map(Expires)
+    type Err = ();
+    fn from_str(s: &str) -> Result<Expires, ()> {
+        tm_from_str(s).map(Expires).ok_or(())
     }
 }
 
diff --git a/src/header/common/host.rs b/src/header/common/host.rs
index 2e0a167cb7..6e0bb06d3d 100644
--- a/src/header/common/host.rs
+++ b/src/header/common/host.rs
@@ -46,7 +46,7 @@ impl Header for Host {
             };
 
             let port = match idx {
-                Some(idx) => s[idx + 1..].parse(),
+                Some(idx) => s[idx + 1..].parse().ok(),
                 None => None
             };
 
diff --git a/src/header/common/if_modified_since.rs b/src/header/common/if_modified_since.rs
index e9d78be38e..11edfc9e94 100644
--- a/src/header/common/if_modified_since.rs
+++ b/src/header/common/if_modified_since.rs
@@ -34,8 +34,9 @@ impl HeaderFormat for IfModifiedSince {
 }
 
 impl FromStr for IfModifiedSince {
-    fn from_str(s: &str) -> Option<IfModifiedSince> {
-        tm_from_str(s).map(IfModifiedSince)
+    type Err = ();
+    fn from_str(s: &str) -> Result<IfModifiedSince, ()> {
+        tm_from_str(s).map(IfModifiedSince).ok_or(())
     }
 }
 
diff --git a/src/header/common/last_modified.rs b/src/header/common/last_modified.rs
index e44b447d54..ae0aafae75 100644
--- a/src/header/common/last_modified.rs
+++ b/src/header/common/last_modified.rs
@@ -34,8 +34,9 @@ impl HeaderFormat for LastModified {
 }
 
 impl FromStr for LastModified {
-    fn from_str(s: &str) -> Option<LastModified> {
-        tm_from_str(s).map(LastModified)
+    type Err = ();
+    fn from_str(s: &str) -> Result<LastModified, ()> {
+        tm_from_str(s).map(LastModified).ok_or(())
     }
 }
 
diff --git a/src/header/common/set_cookie.rs b/src/header/common/set_cookie.rs
index 436fc98ca8..a0e37bc15f 100644
--- a/src/header/common/set_cookie.rs
+++ b/src/header/common/set_cookie.rs
@@ -26,8 +26,8 @@ impl Header for SetCookie {
             match from_utf8(&set_cookies_raw[]) {
                 Ok(s) if !s.is_empty() => {
                     match s.parse() {
-                        Some(cookie) => set_cookies.push(cookie),
-                        None => ()
+                        Ok(cookie) => set_cookies.push(cookie),
+                        Err(_) => ()
                     }
                 },
                 _ => ()
diff --git a/src/header/common/upgrade.rs b/src/header/common/upgrade.rs
index 6e304a701a..9347d3a2da 100644
--- a/src/header/common/upgrade.rs
+++ b/src/header/common/upgrade.rs
@@ -22,12 +22,13 @@ pub enum Protocol {
 }
 
 impl FromStr for Protocol {
-    fn from_str(s: &str) -> Option<Protocol> {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Protocol, ()> {
         if UniCase(s) == UniCase("websocket") {
-            Some(WebSocket)
+            Ok(WebSocket)
         }
         else {
-            Some(ProtocolExt(s.to_string()))
+            Ok(ProtocolExt(s.to_string()))
         }
     }
 }
diff --git a/src/header/mod.rs b/src/header/mod.rs
index 73986e888a..4a9a3a7e98 100644
--- a/src/header/mod.rs
+++ b/src/header/mod.rs
@@ -349,7 +349,7 @@ impl<'a> fmt::Debug for HeaderView<'a> {
 }
 
 impl<'a> Extend<HeaderView<'a>> for Headers {
-    fn extend<I: Iterator<Item=HeaderView<'a>>>(&mut self, mut iter: I) {
+    fn extend<I: Iterator<Item=HeaderView<'a>>>(&mut self, iter: I) {
         for header in iter {
             self.data.insert((*header.0).clone(), (*header.1).clone());
         }
@@ -571,7 +571,7 @@ mod tests {
             }
             // we JUST checked that raw.len() == 1, so raw[0] WILL exist.
             match from_utf8(unsafe { &raw[].get_unchecked(0)[] }) {
-                Ok(s) => FromStr::from_str(s),
+                Ok(s) => FromStr::from_str(s).ok(),
                 Err(_) => None
             }.map(|u| CrazyLength(Some(false), u))
         }
diff --git a/src/header/parsing.rs b/src/header/parsing.rs
index 940fd1a583..16964f261c 100644
--- a/src/header/parsing.rs
+++ b/src/header/parsing.rs
@@ -12,7 +12,7 @@ pub fn from_one_raw_str<T: str::FromStr>(raw: &[Vec<u8>]) -> Option<T> {
     }
     // we JUST checked that raw.len() == 1, so raw[0] WILL exist.
     match str::from_utf8(&raw[0][]) {
-        Ok(s) => str::FromStr::from_str(s),
+        Ok(s) => str::FromStr::from_str(s).ok(),
         Err(_) => None
     }
 }
@@ -34,7 +34,7 @@ pub fn from_one_comma_delimited<T: str::FromStr>(raw: &[u8]) -> Option<Vec<T>> {
             Some(s.as_slice()
                  .split(',')
                  .map(|x| x.trim())
-                 .filter_map(str::FromStr::from_str)
+                 .filter_map(|x| x.parse().ok())
                  .collect())
         }
         Err(_) => None
diff --git a/src/header/shared/encoding.rs b/src/header/shared/encoding.rs
index 8a20447ad6..f78e97f10b 100644
--- a/src/header/shared/encoding.rs
+++ b/src/header/shared/encoding.rs
@@ -37,14 +37,15 @@ impl fmt::Display for Encoding {
 }
 
 impl str::FromStr for Encoding {
-    fn from_str(s: &str) -> Option<Encoding> {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Encoding, ()> {
         match s {
-            "chunked" => Some(Chunked),
-            "deflate" => Some(Deflate),
-            "gzip" => Some(Gzip),
-            "compress" => Some(Compress),
-            "identity" => Some(Identity),
-            _ => Some(EncodingExt(s.to_string()))
+            "chunked" => Ok(Chunked),
+            "deflate" => Ok(Deflate),
+            "gzip" => Ok(Gzip),
+            "compress" => Ok(Compress),
+            "identity" => Ok(Identity),
+            _ => Ok(EncodingExt(s.to_string()))
         }
     }
 }
diff --git a/src/header/shared/quality_item.rs b/src/header/shared/quality_item.rs
index 73eaf05644..0e953f05d7 100644
--- a/src/header/shared/quality_item.rs
+++ b/src/header/shared/quality_item.rs
@@ -38,7 +38,8 @@ impl<T: fmt::Display> fmt::Display for QualityItem<T> {
 }
 
 impl<T: str::FromStr> str::FromStr for QualityItem<T> {
-    fn from_str(s: &str) -> Option<Self> {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Self, ()> {
         // Set defaults used if parsing fails.
         let mut raw_item = s;
         let mut quality = 1f32;
@@ -49,28 +50,28 @@ impl<T: str::FromStr> str::FromStr for QualityItem<T> {
             if start == "q=" || start == "Q=" {
                 let q_part = &parts[0][2..parts[0].len()];
                 if q_part.len() > 5 {
-                    return None;
+                    return Err(());
                 }
-                let x: Option<f32> = q_part.parse();
+                let x: Result<f32, _> = q_part.parse();
                 match x {
-                    Some(q_value) => {
+                    Ok(q_value) => {
                         if 0f32 <= q_value && q_value <= 1f32 {
                             quality = q_value;
                             raw_item = parts[1];
                             } else {
-                                return None;
+                                return Err(());
                             }
                         },
-                    None => return None,
+                    Err(_) => return Err(()),
                 }
             }
         }
-        let x: Option<T> = raw_item.parse();
+        let x: Result<T, _> = raw_item.parse();
         match x {
-            Some(item) => {
-                Some(QualityItem{ item: item, quality: quality, })
+            Ok(item) => {
+                Ok(QualityItem{ item: item, quality: quality, })
             },
-            None => return None,
+            Err(_) => return Err(()),
         }
     }
 }
@@ -103,26 +104,26 @@ fn test_quality_item_show3() {
 
 #[test]
 fn test_quality_item_from_str1() {
-    let x: Option<QualityItem<Encoding>> = "chunked".parse();
+    let x: Result<QualityItem<Encoding>, ()> = "chunked".parse();
     assert_eq!(x.unwrap(), QualityItem{ item: Chunked, quality: 1f32, });
 }
 #[test]
 fn test_quality_item_from_str2() {
-    let x: Option<QualityItem<Encoding>> = "chunked; q=1".parse();
+    let x: Result<QualityItem<Encoding>, ()> = "chunked; q=1".parse();
     assert_eq!(x.unwrap(), QualityItem{ item: Chunked, quality: 1f32, });
 }
 #[test]
 fn test_quality_item_from_str3() {
-    let x: Option<QualityItem<Encoding>> = "gzip; q=0.5".parse();
+    let x: Result<QualityItem<Encoding>, ()> = "gzip; q=0.5".parse();
     assert_eq!(x.unwrap(), QualityItem{ item: Gzip, quality: 0.5f32, });
 }
 #[test]
 fn test_quality_item_from_str4() {
-    let x: Option<QualityItem<Encoding>> = "gzip; q=0.273".parse();
+    let x: Result<QualityItem<Encoding>, ()> = "gzip; q=0.273".parse();
     assert_eq!(x.unwrap(), QualityItem{ item: Gzip, quality: 0.273f32, });
 }
 #[test]
 fn test_quality_item_from_str5() {
-    let x: Option<QualityItem<Encoding>> = "gzip; q=0.2739999".parse();
-    assert_eq!(x, None);
+    let x: Result<QualityItem<Encoding>, ()> = "gzip; q=0.2739999".parse();
+    assert_eq!(x, Err(()));
 }
diff --git a/src/http.rs b/src/http.rs
index 75c2bda42f..2d081bcb43 100644
--- a/src/http.rs
+++ b/src/http.rs
@@ -4,7 +4,7 @@ use std::borrow::IntoCow;
 use std::cmp::min;
 use std::old_io::{self, Reader, IoResult, BufWriter};
 use std::num::from_u16;
-use std::str::{self, FromStr};
+use std::str;
 use std::string::CowString;
 
 use url::Url;
@@ -625,7 +625,7 @@ pub fn read_status<R: Reader>(stream: &mut R) -> HttpResult<RawStatus> {
         try!(stream.read_byte()),
     ];
 
-    let code = match str::from_utf8(code.as_slice()).ok().and_then(FromStr::from_str) {
+    let code = match str::from_utf8(code.as_slice()).ok().and_then(|x| x.parse().ok()) {
         Some(num) => num,
         None => return Err(HttpStatusError)
     };
diff --git a/src/method.rs b/src/method.rs
index 323482f1f0..6fc62ff82b 100644
--- a/src/method.rs
+++ b/src/method.rs
@@ -68,11 +68,12 @@ impl Method {
 }
 
 impl FromStr for Method {
-    fn from_str(s: &str) -> Option<Method> {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Method, ()> {
         if s == "" {
-            None
+            Err(())
         } else {
-            Some(match s {
+            Ok(match s {
                 "OPTIONS" => Options,
                 "GET" => Get,
                 "POST" => Post,
@@ -127,8 +128,8 @@ mod tests {
 
     #[test]
     fn test_from_str() {
-        assert_eq!(Some(Get), FromStr::from_str("GET"));
-        assert_eq!(Some(Extension("MOVE".to_string())),
+        assert_eq!(Ok(Get), FromStr::from_str("GET"));
+        assert_eq!(Ok(Extension("MOVE".to_string())),
                    FromStr::from_str("MOVE"));
     }