diff --git a/src/cargo/cargo.rs b/src/cargo/cargo.rs
index 4d67877afd8acd07a20fbc995df38a23dae2fd0f..8e8996551fa5128c837a1b9fa5e7170b4fe0d1e1 100644
--- a/src/cargo/cargo.rs
+++ b/src/cargo/cargo.rs
@@ -174,10 +174,10 @@ fn print(s: str) {
 }
 
 fn rest(s: str, start: uint) -> str {
-    if (start >= str::len(s)) {
+    if (start >= str::len_chars(s)) {
         ""
     } else {
-        str::slice(s, start, str::len(s))
+        str::slice(s, start, str::len_chars(s))
     }
 }
 
@@ -689,7 +689,7 @@ fn cmd_install(c: cargo) unsafe {
         alt str::index(uuid, '/') {
             option::some(idx) {
                let source = str::slice(uuid, 0u, idx);
-               uuid = str::slice(uuid, idx + 1u, str::len(uuid));
+               uuid = str::slice(uuid, idx + 1u, str::len_chars(uuid));
                install_uuid_specific(c, wd, source, uuid);
             }
             option::none {
@@ -701,7 +701,7 @@ fn cmd_install(c: cargo) unsafe {
         alt str::index(name, '/') {
             option::some(idx) {
                let source = str::slice(name, 0u, idx);
-               name = str::slice(name, idx + 1u, str::len(name));
+               name = str::slice(name, idx + 1u, str::len_chars(name));
                install_named_specific(c, wd, source, name);
             }
             option::none {
diff --git a/src/comp/driver/diagnostic.rs b/src/comp/driver/diagnostic.rs
index 8f0570a434959fc600de840fc6f151014efe36b9..f0c97588f59676178a383cb3bb11731eb47c56b1 100644
--- a/src/comp/driver/diagnostic.rs
+++ b/src/comp/driver/diagnostic.rs
@@ -210,7 +210,7 @@ fn highlight_lines(cm: codemap::codemap, sp: span,
     if elided {
         let last_line = display_lines[vec::len(display_lines) - 1u];
         let s = #fmt["%s:%u ", fm.name, last_line + 1u];
-        let indent = str::len(s);
+        let indent = str::len_bytes(s);
         let out = "";
         while indent > 0u { out += " "; indent -= 1u; }
         out += "...\n";
@@ -228,7 +228,7 @@ fn highlight_lines(cm: codemap::codemap, sp: span,
         while num > 0u { num /= 10u; digits += 1u; }
 
         // indent past |name:## | and the 0-offset column location
-        let left = str::len(fm.name) + digits + lo.col + 3u;
+        let left = str::len_bytes(fm.name) + digits + lo.col + 3u;
         let s = "";
         while left > 0u { str::push_char(s, ' '); left -= 1u; }
 
diff --git a/src/comp/syntax/codemap.rs b/src/comp/syntax/codemap.rs
index 744ea97441d0fdf491bc4f44e42fd72c1b3bd090..6c0182c3411497f0c4d0050543ad1bb68adad39a 100644
--- a/src/comp/syntax/codemap.rs
+++ b/src/comp/syntax/codemap.rs
@@ -158,9 +158,9 @@ fn span_to_lines(sp: span, cm: codemap::codemap) -> @file_lines {
 fn get_line(fm: filemap, line: int) -> str unsafe {
     let begin: uint = fm.lines[line].byte - fm.start_pos.byte;
     let end = alt str::byte_index_from(*fm.src, '\n' as u8, begin,
-                                  str::len(*fm.src)) {
+                                  str::len_bytes(*fm.src)) {
       some(e) { e }
-      none { str::len(*fm.src) }
+      none { str::len_bytes(*fm.src) }
     };
     str::unsafe::slice_bytes(*fm.src, begin, end)
 }
diff --git a/src/comp/syntax/ext/qquote.rs b/src/comp/syntax/ext/qquote.rs
index 3476584aecece6fb168f3fce81db0012ca967a30..e53307b474abf389bab7e9804543cd92662ba02e 100644
--- a/src/comp/syntax/ext/qquote.rs
+++ b/src/comp/syntax/ext/qquote.rs
@@ -214,7 +214,7 @@ fn finish<T: qq_helper>
         if (j < g_len && i == cx.gather[j].lo) {
             assert ch == '$';
             let repl = #fmt("$%u ", j);
-            state = skip(str::len(repl));
+            state = skip(str::len_chars(repl));
             str2 += repl;
         }
         alt state {
diff --git a/src/comp/syntax/print/pp.rs b/src/comp/syntax/print/pp.rs
index 3ee31314299291cf31542cb6c0261ca033e91d5a..9114caea2d4e2ba904dd03d7720d06e91d85d323 100644
--- a/src/comp/syntax/print/pp.rs
+++ b/src/comp/syntax/print/pp.rs
@@ -491,7 +491,7 @@ fn break_offset(p: printer, n: uint, off: int) {
 fn eof(p: printer) { p.pretty_print(EOF); }
 
 fn word(p: printer, wrd: str) {
-    p.pretty_print(STRING(wrd, str::len(wrd) as int));
+    p.pretty_print(STRING(wrd, str::len_bytes(wrd) as int));
 }
 
 fn huge_word(p: printer, wrd: str) {
diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index 2b29bf57eaa10cef5a98f77ce1e0db41c21ee257..288d8a38dda7d16e661067281e7bc64462dbc21c 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -204,7 +204,7 @@ fn head(s: ps, w: str) {
     // outer-box is consistent
     cbox(s, indent_unit);
     // head-box is inconsistent
-    ibox(s, str::len(w) + 1u);
+    ibox(s, str::len_bytes(w) + 1u);
     // keyword that starts the head
     word_nbsp(s, w);
 }
diff --git a/src/fuzzer/fuzzer.rs b/src/fuzzer/fuzzer.rs
index b0a47e4051b3dac3dd3f69ccd4841531e2614a7e..152df70e7a4f444279c18652698ef1c49971daf1 100644
--- a/src/fuzzer/fuzzer.rs
+++ b/src/fuzzer/fuzzer.rs
@@ -287,7 +287,7 @@ fn check_variants_T<T: copy>(
 
 fn last_part(filename: str) -> str {
   let ix = option::get(str::rindex(filename, '/'));
-  str::slice(filename, ix + 1u, str::len(filename) - 3u)
+  str::slice(filename, ix + 1u, str::len_chars(filename) - 3u)
 }
 
 enum happiness { passed, cleanly_rejected(str), known_bug(str), failed(str), }
diff --git a/src/libcore/extfmt.rs b/src/libcore/extfmt.rs
index 30676e34de831b0409af02a9d052f21ecca596fc..5fca4d69f3af1587f89a789572d9aba0fec670ee 100644
--- a/src/libcore/extfmt.rs
+++ b/src/libcore/extfmt.rs
@@ -325,7 +325,7 @@ fn conv_str(cv: conv, s: str) -> str unsafe {
             alt cv.precision {
               count_implied { s }
               count_is(max) {
-                if max as uint < str::len(s) {
+                if max as uint < str::len_chars(s) {
                     str::substr(s, 0u, max as uint)
                 } else { s }
               }
@@ -368,7 +368,7 @@ fn uint_to_str_prec(num: uint, radix: uint, prec: uint) -> str {
                 ""
             } else {
                 let s = uint::to_str(num, radix);
-                let len = str::len(s);
+                let len = str::len_chars(s);
                 if len < prec {
                     let diff = prec - len;
                     let pad = str_init_elt(diff, '0');
@@ -400,7 +400,7 @@ fn pad(cv: conv, s: str, mode: pad_mode) -> str unsafe {
             uwidth = width as uint;
           }
         }
-        let strlen = str::len(s);
+        let strlen = str::len_chars(s);
         if uwidth <= strlen { ret s; }
         let padchar = ' ';
         let diff = uwidth - strlen;
diff --git a/src/libcore/str.rs b/src/libcore/str.rs
index d81f2d45d4080512d437680152c7995474819a4d..de8ba2f28b6ba95019b6c4ad663b3cbc41a1b548 100644
--- a/src/libcore/str.rs
+++ b/src/libcore/str.rs
@@ -86,7 +86,7 @@
    is_not_empty,
    is_whitespace,
    len_bytes,
-   len_chars, len,
+   len_chars, //len,
 
    // Misc
    // FIXME: perhaps some more of this section shouldn't be exported?
@@ -529,7 +529,7 @@ fn split(ss: str, sepfn: fn(cc: char)->bool) -> [str] {
         }
     });
 
-    if len(accum) >= 0u || ends_with_sep {
+    if len_chars(accum) >= 0u || ends_with_sep {
         vv += [accum];
     }
 
@@ -601,7 +601,7 @@ fn lines_any(ss: str) -> [str] {
 */
 fn words(ss: str) -> [str] {
     ret vec::filter( split(ss, {|cc| char::is_whitespace(cc)}),
-                     {|w| 0u < str::len(w)});
+                     {|w| 0u < str::len_chars(w)});
 }
 
 /*
@@ -611,7 +611,7 @@ fn words(ss: str) -> [str] {
 */
 fn windowed(nn: uint, ss: str) -> [str] {
     let ww = [];
-    let len = str::len(ss);
+    let len = str::len_chars(ss);
 
     assert 1u <= nn;
 
@@ -883,7 +883,7 @@ fn byte_index_from(s: str, b: u8, start: uint, end: uint) -> option<uint> {
 // (as option some/none)
 fn rindex(ss: str, cc: char) -> option<uint> {
     let bii = len_bytes(ss);
-    let cii = len(ss);
+    let cii = len_chars(ss);
     while bii > 0u {
         let {ch, prev} = char_range_at_reverse(ss, bii);
         cii -= 1u;
@@ -1008,8 +1008,8 @@ fn starts_with(haystack: str, needle: str) -> bool unsafe {
 needle - The string to look for
 */
 fn ends_with(haystack: str, needle: str) -> bool {
-    let haystack_len: uint = len(haystack);
-    let needle_len: uint = len(needle);
+    let haystack_len: uint = len_chars(haystack);
+    let needle_len: uint = len_chars(needle);
     ret if needle_len == 0u {
             true
         } else if needle_len > haystack_len {
@@ -1079,7 +1079,9 @@ fn len(s: str) -> uint {
     substr_len_chars(s, 0u, len_bytes(s))
 }
 
-fn len_chars(s: str) -> uint { len(s) }
+fn len_chars(s: str) -> uint {
+    substr_len_chars(s, 0u, len_bytes(s))
+}
 
 /*
 Section: Misc
@@ -1529,14 +1531,14 @@ fn test_len() {
         assert (len_bytes("\u2620") == 3u);
         assert (len_bytes("\U0001d11e") == 4u);
 
-        assert (len("") == 0u);
-        assert (len("hello world") == 11u);
-        assert (len("\x63") == 1u);
-        assert (len("\xa2") == 1u);
-        assert (len("\u03c0") == 1u);
-        assert (len("\u2620") == 1u);
-        assert (len("\U0001d11e") == 1u);
-        assert (len("ประเทศไทย中华Việt Nam") == 19u);
+        assert (len_chars("") == 0u);
+        assert (len_chars("hello world") == 11u);
+        assert (len_chars("\x63") == 1u);
+        assert (len_chars("\xa2") == 1u);
+        assert (len_chars("\u03c0") == 1u);
+        assert (len_chars("\u2620") == 1u);
+        assert (len_chars("\U0001d11e") == 1u);
+        assert (len_chars("ประเทศไทย中华Việt Nam") == 19u);
     }
 
     #[test]
diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index 30abbb1e70aa91d9c0abeb100605be69d243a04f..ff2188461504d6acd5c45bbf4f8917729352a992 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -45,7 +45,7 @@ fn splitDirnameBasename (pp: path) -> {dirname: str, basename: str} {
     }
 
     ret {dirname: str::slice(pp, 0u, ii),
-         basename: str::slice(pp, ii + 1u, str::len(pp))};
+         basename: str::slice(pp, ii + 1u, str::len_chars(pp))};
 }
 
 /*
diff --git a/src/libstd/getopts.rs b/src/libstd/getopts.rs
index dba406c889ecddf3597b32c36db891c6c609e0f4..e925cd16e335d1f57151ff48e20767413c290201 100644
--- a/src/libstd/getopts.rs
+++ b/src/libstd/getopts.rs
@@ -79,7 +79,7 @@ enum occur { req, optional, multi, }
 type opt = {name: name, hasarg: hasarg, occur: occur};
 
 fn mkname(nm: str) -> name {
-    ret if str::len(nm) == 1u {
+    ret if str::len_bytes(nm) == 1u {
             short(str::char_at(nm, 0u))
         } else { long(nm) };
 }
diff --git a/src/libstd/json.rs b/src/libstd/json.rs
index 127cd93952e78563e4d411d3ae5b3b952a004fb7..23d70a78bf61abc1464a6f681205bba4aa004a81 100644
--- a/src/libstd/json.rs
+++ b/src/libstd/json.rs
@@ -70,8 +70,8 @@ fn to_str(j: json) -> str {
 }
 
 fn rest(s: str) -> str {
-    assert(str::len(s) >= 1u);
-    str::slice(s, 1u, str::len(s))
+    assert(str::len_chars(s) >= 1u);
+    str::slice(s, 1u, str::len_chars(s))
 }
 
 fn from_str_str(s: str) -> (option<json>, str) {
@@ -99,7 +99,7 @@ fn from_str_str(s: str) -> (option<json>, str) {
             cont;
         } else if (c == '"') {
             ret (some(string(res)),
-                 str::slice(s, pos, str::len(s)));
+                 str::slice(s, pos, str::len_chars(s)));
         }
         res = res + str::from_char(c);
     }
@@ -200,12 +200,12 @@ fn from_str_float(s: str) -> (option<json>, str) {
             }
             '.' { break; }
             _ { ret (some(num(neg * res)),
-                     str::slice(s, opos, str::len(s))); }
+                     str::slice(s, opos, str::len_chars(s))); }
         }
     }
 
     if pos == len {
-        ret (some(num(neg * res)), str::slice(s, pos, str::len(s)));
+        ret (some(num(neg * res)), str::slice(s, pos, str::len_chars(s)));
     }
 
     let dec = 1f;
@@ -220,17 +220,17 @@ fn from_str_float(s: str) -> (option<json>, str) {
                 res += (((c as int) - ('0' as int)) as float) * dec;
             }
             _ { ret (some(num(neg * res)),
-                     str::slice(s, opos, str::len(s))); }
+                     str::slice(s, opos, str::len_chars(s))); }
         }
     }
-    ret (some(num(neg * res)), str::slice(s, pos, str::len(s)));
+    ret (some(num(neg * res)), str::slice(s, pos, str::len_chars(s)));
 }
 
 fn from_str_bool(s: str) -> (option<json>, str) {
     if (str::starts_with(s, "true")) {
-        (some(boolean(true)), str::slice(s, 4u, str::len(s)))
+        (some(boolean(true)), str::slice(s, 4u, str::len_chars(s)))
     } else if (str::starts_with(s, "false")) {
-        (some(boolean(false)), str::slice(s, 5u, str::len(s)))
+        (some(boolean(false)), str::slice(s, 5u, str::len_chars(s)))
     } else {
         (none, s)
     }
@@ -238,7 +238,7 @@ fn from_str_bool(s: str) -> (option<json>, str) {
 
 fn from_str_null(s: str) -> (option<json>, str) {
     if (str::starts_with(s, "null")) {
-        (some(null), str::slice(s, 4u, str::len(s)))
+        (some(null), str::slice(s, 4u, str::len_chars(s)))
     } else {
         (none, s)
     }
diff --git a/src/libstd/rand.rs b/src/libstd/rand.rs
index 35525b70710ac4f6a6cb0514758e041a1c3064f2..33fac40fcccc39bfbe8dc1f6b63608d13d222a98 100644
--- a/src/libstd/rand.rs
+++ b/src/libstd/rand.rs
@@ -77,7 +77,7 @@ fn gen_str(len: uint) -> str {
             let i = 0u;
             while (i < len) {
                 let n = rustrt::rand_next(**self) as uint %
-                    str::len(charset);
+                    str::len_bytes(charset);
                 s = s + str::from_char(str::char_at(charset, n));
                 i += 1u;
             }
@@ -130,8 +130,8 @@ fn genstr() {
         log(debug, r.gen_str(10u));
         log(debug, r.gen_str(10u));
         log(debug, r.gen_str(10u));
-        assert(str::len(r.gen_str(10u)) == 10u);
-        assert(str::len(r.gen_str(16u)) == 16u);
+        assert(str::len_bytes(r.gen_str(10u)) == 10u);
+        assert(str::len_bytes(r.gen_str(16u)) == 16u);
     }
 }
 
diff --git a/src/libstd/rope.rs b/src/libstd/rope.rs
index 07ee837a9b9188ac750e4f3ac9df898f8e42e226..3f330c3586d463e81c216c8880bfee8029494391 100644
--- a/src/libstd/rope.rs
+++ b/src/libstd/rope.rs
@@ -1373,7 +1373,7 @@ fn of_string1() {
         let sample = @"0123456789ABCDE";
         let r      = of_str(sample);
 
-        assert char_len(r) == str::len(*sample);
+        assert char_len(r) == str::len_chars(*sample);
         assert rope_to_string(r) == *sample;
     }
 
@@ -1384,7 +1384,7 @@ fn of_string2() {
         while i < 10 { *buf = *buf + *buf; i+=1;}
         let sample = @*buf;
         let r      = of_str(sample);
-        assert char_len(r) == str::len(*sample);
+        assert char_len(r) == str::len_chars(*sample);
         assert rope_to_string(r) == *sample;
 
         let string_iter = 0u;
@@ -1427,7 +1427,7 @@ fn iter1() {
             }
         }
 
-        assert len == str::len(*sample);
+        assert len == str::len_chars(*sample);
     }
 
     #[test]
diff --git a/src/rustdoc/desc_to_brief_pass.rs b/src/rustdoc/desc_to_brief_pass.rs
index b506f502933750ec2e9f41ee4a1bfd23e7bd687e..82ae2ff8fed7b7b61de0029e7c892431d3305b2c 100644
--- a/src/rustdoc/desc_to_brief_pass.rs
+++ b/src/rustdoc/desc_to_brief_pass.rs
@@ -175,7 +175,7 @@ fn parse_desc(desc: str) -> (option<str>, option<str>) {
 
     if check vec::is_not_empty(paras) {
         let maybe_brief = vec::head(paras);
-        if str::len(maybe_brief) <= max_brief_len {
+        if str::len_bytes(maybe_brief) <= max_brief_len {
             let desc_paras = vec::tail(paras);
             let desc = if vec::is_not_empty(desc_paras) {
                 some(str::connect(desc_paras, "\n\n"))
diff --git a/src/rustdoc/unindent_pass.rs b/src/rustdoc/unindent_pass.rs
index b52316ccb15b9c05eb8d98873d61a2dacf170856..d8f56e20479446999391853884ab0b682049b94d 100644
--- a/src/rustdoc/unindent_pass.rs
+++ b/src/rustdoc/unindent_pass.rs
@@ -68,7 +68,7 @@ fn unindent(s: str) -> str {
                 line
             } else {
                 assert str::len_bytes(line) >= min_indent;
-                str::slice(line, min_indent, str::len(line))
+                str::slice(line, min_indent, str::len_chars(line))
             }
         };
         str::connect(unindented, "\n")
diff --git a/src/test/run-pass/utf8_chars.rs b/src/test/run-pass/utf8_chars.rs
index cd591866c248856710b3bca99eddf6ee0d92052d..fbb66b5a1ca48b44ce5170a0c0020626f1ea4464 100644
--- a/src/test/run-pass/utf8_chars.rs
+++ b/src/test/run-pass/utf8_chars.rs
@@ -8,7 +8,7 @@ fn main() {
     let s: str = str::from_chars(chs);
 
     assert (str::len_bytes(s) == 10u);
-    assert (str::len(s) == 4u);
+    assert (str::len_chars(s) == 4u);
     assert (vec::len::<char>(str::chars(s)) == 4u);
     assert (str::eq(str::from_chars(str::chars(s)), s));
     assert (str::char_at(s, 0u) == 'e');