diff --git a/src/libcore/fmt/num.rs b/src/libcore/fmt/num.rs
index 81e84c447e796..a4fd5bb92e697 100644
--- a/src/libcore/fmt/num.rs
+++ b/src/libcore/fmt/num.rs
@@ -119,7 +119,7 @@ pub struct Radix {
 
 impl Radix {
     fn new(base: u8) -> Radix {
-        assert!(2 <= base && base <= 36, "the base must be in the range of 0..36: {}", base);
+        assert!(2 <= base && base <= 36, "the base must be in the range of 2..36: {}", base);
         Radix { base: base }
     }
 }