diff --git a/src/libstd/sys/unix/rand.rs b/src/libstd/sys/unix/rand.rs
index 3f7f067149084..01c0ada4ffbe5 100644
--- a/src/libstd/sys/unix/rand.rs
+++ b/src/libstd/sys/unix/rand.rs
@@ -183,34 +183,10 @@ mod imp {
 mod imp {
     #[link(name = "zircon")]
     extern {
-        fn zx_cprng_draw_new(buffer: *mut u8, len: usize) -> i32;
-    }
-
-    fn getrandom(buf: &mut [u8]) -> Result<usize, i32> {
-        unsafe {
-            let status = zx_cprng_draw_new(buf.as_mut_ptr(), buf.len());
-            if status == 0 {
-                Ok(buf.len())
-            } else {
-                Err(status)
-            }
-        }
+        fn zx_cprng_draw(buffer: *mut u8, len: usize);
     }
 
     pub fn fill_bytes(v: &mut [u8]) {
-        let mut buf = v;
-        while !buf.is_empty() {
-            let ret = getrandom(buf);
-            match ret {
-                Err(err) => {
-                    panic!("kernel zx_cprng_draw call failed! (returned {}, buf.len() {})",
-                        err, buf.len())
-                }
-                Ok(actual) => {
-                    let move_buf = buf;
-                    buf = &mut move_buf[(actual as usize)..];
-                }
-            }
-        }
+        unsafe { zx_cprng_draw(v.as_mut_ptr(), v.len()) }
     }
 }