diff --git a/c2hs/c/CLexer.x b/c2hs/c/CLexer.x
index 77702ed..1cd2483 100644
--- a/c2hs/c/CLexer.x
+++ b/c2hs/c/CLexer.x
@@ -68,3 +68,3 @@ module CLexer (lexC, parseError) where
 
-import Data.Char      (isDigit)
+import Data.Char      (ord, isDigit)
 import Data.Word      (Word8)
