diff --git a/src/lib/fs.rs b/src/lib/fs.rs
index 8d5cd3a4c7bc..99c823381226 100644
--- a/src/lib/fs.rs
+++ b/src/lib/fs.rs
@@ -1,4 +1,5 @@
 
+import os::getcwd;
 
 native "rust" mod rustrt {
     fn rust_file_is_dir(str path) -> int;
@@ -56,6 +57,23 @@ fn list_dir(path p) -> vec[str] {
     }
     ret full_paths;
 }
+
+// FIXME: Windows absolute paths can start with \ for C:\ or
+// whatever... However, we're under MinGW32 so we have the same rules and
+// posix has.
+fn path_is_absolute(path p) -> bool {
+    ret p.(0) == '/';
+}
+
+fn make_absolute(path p) -> path {
+    if(path_is_absolute(p)) {
+        ret p;
+    }
+    else {
+        ret connect(getcwd(), p);
+    }
+}
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;
diff --git a/src/lib/linux_os.rs b/src/lib/linux_os.rs
index 228fc2d4d1ae..b3d5cea3ac3b 100644
--- a/src/lib/linux_os.rs
+++ b/src/lib/linux_os.rs
@@ -72,6 +72,14 @@ fn waitpid(int pid) -> int {
     assert (os::libc::waitpid(pid, vec::buf(status), 0) != -1);
     ret status.(0);
 }
+
+native "rust" mod rustrt {
+    fn rust_getcwd() -> str;
+}
+
+fn getcwd() -> str { ret rustrt::rust_getcwd(); }
+
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;
diff --git a/src/lib/macos_os.rs b/src/lib/macos_os.rs
index 2741ca64aed1..2ab7e7b748a5 100644
--- a/src/lib/macos_os.rs
+++ b/src/lib/macos_os.rs
@@ -69,6 +69,14 @@ fn waitpid(int pid) -> int {
     assert (os::libc::waitpid(pid, vec::buf(status), 0) != -1);
     ret status.(0);
 }
+
+native "rust" mod rustrt {
+    fn rust_getcwd() -> str;
+}
+
+fn getcwd() -> str { ret rustrt::rust_getcwd(); }
+
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;
diff --git a/src/lib/posix_fs.rs b/src/lib/posix_fs.rs
index 1835b92c2b0e..c962fa7250f6 100644
--- a/src/lib/posix_fs.rs
+++ b/src/lib/posix_fs.rs
@@ -1,5 +1,4 @@
 
-
 native "rust" mod rustrt {
     fn rust_list_files(str path) -> vec[str];
     fn rust_dirent_filename(os::libc::dirent ent) -> str;
@@ -36,6 +35,7 @@ fn list_dir(str path) -> vec[str] {
 const char path_sep = '/';
 
 const char alt_path_sep = '/';
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;
diff --git a/src/lib/win32_fs.rs b/src/lib/win32_fs.rs
index 6a9c521a598d..4b3d6ba10bc7 100644
--- a/src/lib/win32_fs.rs
+++ b/src/lib/win32_fs.rs
@@ -7,7 +7,6 @@ native "rust" mod rustrt {
 
 fn list_dir(str path) -> vec[str] { ret rustrt::rust_list_files(path + "*"); }
 
-
 /* FIXME: win32 path handling actually accepts '/' or '\' and has subtly
  * different semantics for each. Since we build on mingw, we are usually
  * dealing with /-separated paths. But the whole interface to splitting and
diff --git a/src/lib/win32_os.rs b/src/lib/win32_os.rs
index 38e53fa2ff2a..1a8d2071d2e4 100644
--- a/src/lib/win32_os.rs
+++ b/src/lib/win32_os.rs
@@ -59,9 +59,13 @@ fn fd_FILE(int fd) -> libc::FILE { ret libc::_fdopen(fd, str::buf("r")); }
 
 native "rust" mod rustrt {
     fn rust_process_wait(int handle) -> int;
+    fn rust_getcwd() -> str;
 }
 
 fn waitpid(int pid) -> int { ret rustrt::rust_process_wait(pid); }
+
+fn getcwd() -> str { ret rustrt::rust_getcwd(); }
+
 // Local Variables:
 // mode: rust;
 // fill-column: 78;
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index c713a923d460..afa022fe533a 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -55,6 +55,36 @@ last_os_error(rust_task *task) {
     return st;
 }
 
+extern "C" CDECL rust_str *
+rust_getcwd(rust_task *task) {
+    rust_dom *dom = task->dom;
+    LOG(task, task, "rust_getcwd()");
+
+    char cbuf[BUF_BYTES];
+
+#if defined(__WIN32__)
+    if (!_getcwd(cbuf, sizeof(cbuf))) {
+#else
+        if (!getcwd(cbuf, sizeof(cbuf))) {
+#endif
+        task->fail(1);
+        return NULL;
+    }
+
+    size_t fill = strlen(cbuf) + 1;
+    size_t alloc = next_power_of_two(sizeof(rust_str) + fill);
+    void *mem = dom->malloc(alloc, memory_region::LOCAL);
+    if (!mem) {
+        task->fail(1);
+        return NULL;
+    }
+
+    rust_str *st;
+    st = new (mem) rust_str(dom, alloc, fill, (const uint8_t *)cbuf);
+
+    return st;    
+}
+
 extern "C" CDECL
 void squareroot(rust_task *task, double *input, double *output) {
     *output = sqrt(*input);