diff --git a/bug.cabal b/bug.cabal
--- a/bug.cabal
+++ b/bug.cabal
@@ -1,7 +1,7 @@
 name:
   bug
 version:
-  1
+  1.0.1
 synopsis:
   Better alternatives to the "error" function
 category:
@@ -44,4 +44,4 @@
     Bug.Formatting
   build-depends:
     template-haskell >= 2.8 && < 3,
-    base >= 4 && < 5
+    base >= 4.7 && < 5
diff --git a/library/Bug.hs b/library/Bug.hs
--- a/library/Bug.hs
+++ b/library/Bug.hs
@@ -2,6 +2,7 @@
 where
 
 import Prelude
+import Data.Functor
 import Language.Haskell.TH.Syntax
 import qualified Bug.Formatting as B