diff --git a/src/Vervis/Foundation.hs b/src/Vervis/Foundation.hs
index 9cc07f9..d7495f9 100644
--- a/src/Vervis/Foundation.hs
+++ b/src/Vervis/Foundation.hs
@@ -626,7 +626,7 @@ instance YesodHttpSig App where
             existsInDB = isJust mvkid
         now <- liftIO getCurrentTime
         let stillValid Nothing        = True
-            stillValue (Just expires) = expires > now
+            stillValid (Just expires) = expires > now
         (write, key', mexpires') <-
             if verify' key && stillValid mexpires
                 then return (not existsInDB, key, mexpires)