diff --git a/src/libcore/char/methods.rs b/src/libcore/char/methods.rs
index fc212aa4f2086..46b201f7bbf2c 100644
--- a/src/libcore/char/methods.rs
+++ b/src/libcore/char/methods.rs
@@ -122,12 +122,27 @@ impl char {
     #[inline]
     pub fn to_digit(self, radix: u32) -> Option<u32> {
         assert!(radix <= 36, "to_digit: radix is too high (maximum 36)");
-        let val = match self {
-          '0' ..= '9' => self as u32 - '0' as u32,
-          'a' ..= 'z' => self as u32 - 'a' as u32 + 10,
-          'A' ..= 'Z' => self as u32 - 'A' as u32 + 10,
-          _ => return None,
+        if radix == 10 {
+            return match self {
+                '0' ..= '9' => Some(self as u32 - '0' as u32),
+                _ => None,
+            };
+        }
+
+        let val = if radix < 10  {
+            match self {
+                '0' ..= '9' => self as u32 - '0' as u32,
+                _ => return None,
+            }
+        } else {
+            match self {
+                '0'..='9' => self as u32 - '0' as u32,
+                'a'..='z' => self as u32 - 'a' as u32 + 10,
+                'A'..='Z' => self as u32 - 'A' as u32 + 10,
+                _ => return None,
+            }
         };
+
         if val < radix { Some(val) }
         else { None }
     }