diff --git a/src/libcore/benches/ascii.rs b/src/libcore/benches/ascii.rs
index 968d28a9958..635537e3121 100644
--- a/src/libcore/benches/ascii.rs
+++ b/src/libcore/benches/ascii.rs
@@ -224,6 +224,18 @@ fn is_ascii_lowercase(b: u8) -> bool {
         }
     }
 
+    fn case14_subtract_multiplied_bool_match_range(bytes: &mut [u8]) {
+        fn is_ascii_lowercase(b: u8) -> bool {
+            match b {
+                b'a'...b'z' => true,
+                _ => false
+            }
+        }
+        for byte in bytes {
+            *byte -= (b'a' - b'A') * is_ascii_lowercase(*byte) as u8
+        }
+    }
+
     @iter
 
     is_ascii,