diff --git a/src/libsemver/lib.rs b/src/libsemver/lib.rs
index 2707ccd4f08..3035b305617 100644
--- a/src/libsemver/lib.rs
+++ b/src/libsemver/lib.rs
@@ -50,7 +50,7 @@ use std::strbuf::StrBuf;
 #[allow(missing_doc)]
 pub enum Identifier {
     Numeric(uint),
-    AlphaNumeric(~str)
+    AlphaNumeric(StrBuf)
 }
 
 impl cmp::Ord for Identifier {
@@ -158,7 +158,7 @@ impl cmp::Ord for Version {
 }
 
 fn take_nonempty_prefix<T:Iterator<char>>(rdr: &mut T, pred: |char| -> bool)
-                        -> (~str, Option<char>) {
+                        -> (StrBuf, Option<char>) {
     let mut buf = StrBuf::new();
     let mut ch = rdr.next();
     loop {
@@ -171,12 +171,12 @@ fn take_nonempty_prefix<T:Iterator<char>>(rdr: &mut T, pred: |char| -> bool)
             }
         }
     }
-    (buf.into_owned(), ch)
+    (buf, ch)
 }
 
 fn take_num<T: Iterator<char>>(rdr: &mut T) -> Option<(uint, Option<char>)> {
     let (s, ch) = take_nonempty_prefix(rdr, char::is_digit);
-    match from_str::<uint>(s) {
+    match from_str::<uint>(s.as_slice()) {
         None => None,
         Some(i) => Some((i, ch))
     }
@@ -184,8 +184,8 @@ fn take_num<T: Iterator<char>>(rdr: &mut T) -> Option<(uint, Option<char>)> {
 
 fn take_ident<T: Iterator<char>>(rdr: &mut T) -> Option<(Identifier, Option<char>)> {
     let (s,ch) = take_nonempty_prefix(rdr, char::is_alphanumeric);
-    if s.chars().all(char::is_digit) {
-        match from_str::<uint>(s) {
+    if s.as_slice().chars().all(char::is_digit) {
+        match from_str::<uint>(s.as_slice()) {
             None => None,
             Some(i) => Some((Numeric(i), ch))
         }
@@ -308,14 +308,14 @@ fn test_parse() {
         major: 1u,
         minor: 2u,
         patch: 3u,
-        pre: vec!(AlphaNumeric("alpha1".to_owned())),
+        pre: vec!(AlphaNumeric("alpha1".to_strbuf())),
         build: vec!(),
     }));
     assert!(parse("  1.2.3-alpha1  ") == Some(Version {
         major: 1u,
         minor: 2u,
         patch: 3u,
-        pre: vec!(AlphaNumeric("alpha1".to_owned())),
+        pre: vec!(AlphaNumeric("alpha1".to_strbuf())),
         build: vec!()
     }));
     assert!(parse("1.2.3+build5") == Some(Version {
@@ -323,37 +323,37 @@ fn test_parse() {
         minor: 2u,
         patch: 3u,
         pre: vec!(),
-        build: vec!(AlphaNumeric("build5".to_owned()))
+        build: vec!(AlphaNumeric("build5".to_strbuf()))
     }));
     assert!(parse("  1.2.3+build5  ") == Some(Version {
         major: 1u,
         minor: 2u,
         patch: 3u,
         pre: vec!(),
-        build: vec!(AlphaNumeric("build5".to_owned()))
+        build: vec!(AlphaNumeric("build5".to_strbuf()))
     }));
     assert!(parse("1.2.3-alpha1+build5") == Some(Version {
         major: 1u,
         minor: 2u,
         patch: 3u,
-        pre: vec!(AlphaNumeric("alpha1".to_owned())),
-        build: vec!(AlphaNumeric("build5".to_owned()))
+        pre: vec!(AlphaNumeric("alpha1".to_strbuf())),
+        build: vec!(AlphaNumeric("build5".to_strbuf()))
     }));
     assert!(parse("  1.2.3-alpha1+build5  ") == Some(Version {
         major: 1u,
         minor: 2u,
         patch: 3u,
-        pre: vec!(AlphaNumeric("alpha1".to_owned())),
-        build: vec!(AlphaNumeric("build5".to_owned()))
+        pre: vec!(AlphaNumeric("alpha1".to_strbuf())),
+        build: vec!(AlphaNumeric("build5".to_strbuf()))
     }));
     assert!(parse("1.2.3-1.alpha1.9+build5.7.3aedf  ") == Some(Version {
         major: 1u,
         minor: 2u,
         patch: 3u,
-        pre: vec!(Numeric(1),AlphaNumeric("alpha1".to_owned()),Numeric(9)),
-        build: vec!(AlphaNumeric("build5".to_owned()),
+        pre: vec!(Numeric(1),AlphaNumeric("alpha1".to_strbuf()),Numeric(9)),
+        build: vec!(AlphaNumeric("build5".to_strbuf()),
                  Numeric(7),
-                 AlphaNumeric("3aedf".to_owned()))
+                 AlphaNumeric("3aedf".to_strbuf()))
     }));
 
 }
@@ -377,10 +377,14 @@ fn test_ne() {
 
 #[test]
 fn test_show() {
-    assert_eq!(format!("{}", parse("1.2.3").unwrap()), "1.2.3".to_owned());
-    assert_eq!(format!("{}", parse("1.2.3-alpha1").unwrap()), "1.2.3-alpha1".to_owned());
-    assert_eq!(format!("{}", parse("1.2.3+build.42").unwrap()), "1.2.3+build.42".to_owned());
-    assert_eq!(format!("{}", parse("1.2.3-alpha1+42").unwrap()), "1.2.3-alpha1+42".to_owned());
+    assert_eq!(format_strbuf!("{}", parse("1.2.3").unwrap()),
+               "1.2.3".to_strbuf());
+    assert_eq!(format_strbuf!("{}", parse("1.2.3-alpha1").unwrap()),
+               "1.2.3-alpha1".to_strbuf());
+    assert_eq!(format_strbuf!("{}", parse("1.2.3+build.42").unwrap()),
+               "1.2.3+build.42".to_strbuf());
+    assert_eq!(format_strbuf!("{}", parse("1.2.3-alpha1+42").unwrap()),
+               "1.2.3-alpha1+42".to_strbuf());
 }
 
 #[test]