diff --git a/src/Makefile b/src/Makefile
index aaf2e94f68e..792eeec0a3b 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -395,6 +395,7 @@ TEST_XFAILS_X86 :=  $(TASK_XFAILS) \
                     test/run-pass/fn-lval.rs \
                     test/run-pass/generic-fn-infer.rs \
                     test/run-pass/generic-recursive-tag.rs \
+                    test/run-pass/int-lib.rs \
                     test/run-pass/iter-ret.rs \
                     test/run-pass/lib-deque.rs \
                     test/run-pass/lib-map.rs \
@@ -464,6 +465,7 @@ TEST_XFAILS_LLVM := $(TASK_XFAILS) \
                       import.rs \
                       inner-module.rs \
                       integral-indexing.rs \
+                      int-lib.rs \
                       iter-range.rs \
                       iter-ret.rs \
                       large-records.rs \
diff --git a/src/lib/_int.rs b/src/lib/_int.rs
index 03017259d52..e76c2bf5062 100644
--- a/src/lib/_int.rs
+++ b/src/lib/_int.rs
@@ -45,7 +45,7 @@ fn next_power_of_two(uint n) -> uint {
   ret tmp + 1u;
 }
 
-fn uto_string(mutable uint n, uint radix) -> str
+fn uto_str(mutable uint n, uint radix) -> str
 {
   check (0u < radix && radix <= 16u);
   fn digit(uint n) -> str {
@@ -60,12 +60,12 @@ fn uto_string(mutable uint n, uint radix) -> str
       case (7u) { ret "7"; }
       case (8u) { ret "8"; }
       case (9u) { ret "9"; }
-      case (10u) { ret "A"; }
-      case (11u) { ret "B"; }
-      case (12u) { ret "C"; }
-      case (13u) { ret "D"; }
-      case (14u) { ret "E"; }
-      case (15u) { ret "F"; }
+      case (10u) { ret "a"; }
+      case (11u) { ret "b"; }
+      case (12u) { ret "c"; }
+      case (13u) { ret "d"; }
+      case (14u) { ret "e"; }
+      case (15u) { ret "f"; }
     }
   }
 
@@ -79,12 +79,12 @@ fn uto_string(mutable uint n, uint radix) -> str
   ret s;
 }
 
-fn to_string(mutable int n, uint radix) -> str
+fn to_str(mutable int n, uint radix) -> str
 {
   check (0u < radix && radix <= 16u);
   if (n < 0) {
-    ret "-" + uto_string((-n) as uint, radix);
+    ret "-" + uto_str((-n) as uint, radix);
   } else {
-    ret uto_string(n as uint, radix);
+    ret uto_str(n as uint, radix);
   }
 }
diff --git a/src/lib/_io.rs b/src/lib/_io.rs
index dbd60e63d6a..93d06d416fb 100644
--- a/src/lib/_io.rs
+++ b/src/lib/_io.rs
@@ -125,8 +125,8 @@ fn file_writer(str path,
 {
   unsafe obj fw(buf_writer out) {
     fn write_str(str s)   { out.write(_str.bytes(s)); }
-    fn write_int(int n)   { out.write(_str.bytes(_int.to_string(n, 10u))); }
-    fn write_uint(uint n) { out.write(_str.bytes(_int.uto_string(n, 10u))); }
+    fn write_int(int n)   { out.write(_str.bytes(_int.to_str(n, 10u))); }
+    fn write_uint(uint n) { out.write(_str.bytes(_int.uto_str(n, 10u))); }
   }
   ret fw(new_buf_writer(path, flags));
 }
diff --git a/src/test/run-pass/int-lib.rs b/src/test/run-pass/int-lib.rs
new file mode 100644
index 00000000000..ce39de43921
--- /dev/null
+++ b/src/test/run-pass/int-lib.rs
@@ -0,0 +1,15 @@
+use std;
+
+import std._int;
+
+fn test_to_str() {
+  check (_int.to_str(0, 10u) == "0");
+  check (_int.to_str(1, 10u) == "1");
+  check (_int.to_str(-1, 10u) == "-1");
+  check (_int.to_str(255, 16u) == "ff");
+  check (_int.to_str(-71, 36u) == "-1z");
+}
+
+fn main() {
+  test_to_str();
+}