diff --git a/src/libstd/fs.rs b/src/libstd/fs.rs
index 5f91d173ed2ac..ef530a124214e 100644
--- a/src/libstd/fs.rs
+++ b/src/libstd/fs.rs
@@ -97,7 +97,7 @@ pub struct OpenOptions(fs_imp::OpenOptions);
 /// functionality, such as mode bits, is available through the
 /// `os::unix::PermissionsExt` trait.
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct Permissions(fs_imp::FilePermissions);
+pub struct Permissions(fs_imp::Permissions);
 
 impl File {
     /// Attempts to open a file in read-only mode.
@@ -319,8 +319,8 @@ impl Permissions {
     }
 }
 
-impl FromInner<fs_imp::FilePermissions> for Permissions {
-    fn from_inner(f: fs_imp::FilePermissions) -> Permissions {
+impl FromInner<fs_imp::Permissions> for Permissions {
+    fn from_inner(f: fs_imp::Permissions) -> Permissions {
         Permissions(f)
     }
 }
@@ -521,7 +521,15 @@ pub fn read_link<P: AsPath + ?Sized>(path: &P) -> io::Result<PathBuf> {
 /// This function will return an error if the user lacks permissions to make a
 /// new directory at the provided `path`, or if the directory already exists.
 pub fn create_dir<P: AsPath + ?Sized>(path: &P) -> io::Result<()> {
-    fs_imp::mkdir(path.as_path())
+    #[cfg(windows)]
+    fn mkdir(path: &Path) -> io::Result<()> {
+        fs_imp::mkdir(path)
+    }
+    #[cfg(unix)]
+    fn mkdir(path: &Path) -> io::Result<()> {
+        fs_imp::mkdir(path, FromInner::from_inner(0o777))
+    }
+    mkdir(path.as_path())
 }
 
 /// Recursively create a directory and all of its parent components if they
diff --git a/src/libstd/sys/unix/fs2.rs b/src/libstd/sys/unix/fs2.rs
index e5904b074bcb9..b847aa9c63e98 100644
--- a/src/libstd/sys/unix/fs2.rs
+++ b/src/libstd/sys/unix/fs2.rs
@@ -50,7 +50,7 @@ pub struct OpenOptions {
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct FilePermissions { mode: mode_t }
+pub struct Permissions { mode: mode_t }
 
 impl FileAttr {
     pub fn is_dir(&self) -> bool {
@@ -60,8 +60,8 @@ impl FileAttr {
         (self.stat.st_mode as mode_t) & libc::S_IFMT == libc::S_IFREG
     }
     pub fn size(&self) -> u64 { self.stat.st_size as u64 }
-    pub fn perm(&self) -> FilePermissions {
-        FilePermissions { mode: (self.stat.st_mode as mode_t) & 0o777 }
+    pub fn perm(&self) -> Permissions {
+        Permissions { mode: (self.stat.st_mode as mode_t) & 0o777 }
     }
 
     pub fn accessed(&self) -> u64 {
@@ -77,7 +77,7 @@ impl FileAttr {
     }
 }
 
-impl FilePermissions {
+impl Permissions {
     pub fn readonly(&self) -> bool { self.mode & 0o222 == 0 }
     pub fn set_readonly(&mut self, readonly: bool) {
         if readonly {
@@ -88,9 +88,9 @@ impl FilePermissions {
     }
 }
 
-impl FromInner<i32> for FilePermissions {
-    fn from_inner(mode: i32) -> FilePermissions {
-        FilePermissions { mode: mode as mode_t }
+impl FromInner<i32> for Permissions {
+    fn from_inner(mode: i32) -> Permissions {
+        Permissions { mode: mode as mode_t }
     }
 }
 
@@ -272,9 +272,9 @@ fn cstr(path: &Path) -> CString {
     CString::from_slice(path.as_os_str().as_bytes())
 }
 
-pub fn mkdir(p: &Path) -> io::Result<()> {
+pub fn mkdir(p: &Path, perms: Permissions) -> io::Result<()> {
     let p = cstr(p);
-    try!(cvt(unsafe { libc::mkdir(p.as_ptr(), 0o777) }));
+    try!(cvt(unsafe { libc::mkdir(p.as_ptr(), perms.mode) }));
     Ok(())
 }
 
@@ -304,7 +304,7 @@ pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
     Ok(())
 }
 
-pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
+pub fn set_perm(p: &Path, perm: Permissions) -> io::Result<()> {
     let p = cstr(p);
     try!(cvt_r(|| unsafe { libc::chmod(p.as_ptr(), perm.mode) }));
     Ok(())
diff --git a/src/libstd/sys/windows/fs2.rs b/src/libstd/sys/windows/fs2.rs
index 8abcd90efe857..86112e0ac8dc1 100644
--- a/src/libstd/sys/windows/fs2.rs
+++ b/src/libstd/sys/windows/fs2.rs
@@ -48,7 +48,7 @@ pub struct OpenOptions {
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct FilePermissions { attrs: libc::DWORD }
+pub struct Permissions { attrs: libc::DWORD }
 
 impl Iterator for ReadDir {
     type Item = io::Result<DirEntry>;
@@ -266,8 +266,8 @@ impl FileAttr {
     pub fn size(&self) -> u64 {
         ((self.data.nFileSizeHigh as u64) << 32) | (self.data.nFileSizeLow as u64)
     }
-    pub fn perm(&self) -> FilePermissions {
-        FilePermissions { attrs: self.data.dwFileAttributes }
+    pub fn perm(&self) -> Permissions {
+        Permissions { attrs: self.data.dwFileAttributes }
     }
 
     pub fn accessed(&self) -> u64 { self.to_ms(&self.data.ftLastAccessTime) }
@@ -281,7 +281,7 @@ impl FileAttr {
     }
 }
 
-impl FilePermissions {
+impl Permissions {
     pub fn readonly(&self) -> bool {
         self.attrs & c::FILE_ATTRIBUTE_READONLY != 0
     }
@@ -390,7 +390,7 @@ pub fn stat(p: &Path) -> io::Result<FileAttr> {
     }
 }
 
-pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
+pub fn set_perm(p: &Path, perm: Permissions) -> io::Result<()> {
     let p = to_utf16(p);
     unsafe {
         try!(cvt(c::SetFileAttributesW(p.as_ptr(), perm.attrs)));