diff --git a/src/libstd/run.rs b/src/libstd/run.rs
index b6cc556af106..2a8d29214fae 100644
--- a/src/libstd/run.rs
+++ b/src/libstd/run.rs
@@ -746,7 +746,7 @@ fn with_envp<T>(env: Option<&[(~str, ~str)]>, cb: &fn(*mut c_void) -> T) -> T {
         let mut blk = ~[];
         for es.iter().advance |pair| {
             let kv = fmt!("%s=%s", pair.first(), pair.second());
-            blk.push_all(kv.as_bytes_with_null_consume());
+            blk.push_all(kv.to_bytes_with_null());
         }
         blk.push(0);
         blk.as_imm_buf(|p, _len|