diff --git a/src/mktemp/tempdir.rs b/src/mktemp/tempdir.rs
index 186bcd8f5..a2b3ec86c 100644
--- a/src/mktemp/tempdir.rs
+++ b/src/mktemp/tempdir.rs
@@ -11,7 +11,7 @@ use std::path::Path;
 // enough that an attacker will run out of luck before we run out of patience.
 const NUM_RETRIES: u32 = 1 << 31;
 
-#[cfg(unix)]
+#[cfg(any(unix, target_os = "redox"))]
 fn create_dir<P: AsRef<Path>>(path: P) -> IOResult<()> {
     use std::fs::DirBuilder;
     use std::os::unix::fs::DirBuilderExt;