diff --git a/Data/Syntax/Pretty.hs b/Data/Syntax/Pretty.hs
--- a/Data/Syntax/Pretty.hs
+++ b/Data/Syntax/Pretty.hs
@@ -35,7 +35,7 @@
     simap ai (Printer f) = Printer (apply ai >=> f)
 
 instance SemiIsoApply Printer where
-    sipure _ = Printer (\_ -> Right mempty)
+    sipure ai = Printer (\a -> either Left (\_ -> Right mempty) (apply ai a))
     (Printer f) /*/ (Printer g) = Printer (\(a, b) -> (<>) <$> f a <*> g b)
 
 instance SemiIsoAlternative Printer where
diff --git a/syntax-pretty.cabal b/syntax-pretty.cabal
--- a/syntax-pretty.cabal
+++ b/syntax-pretty.cabal
@@ -1,5 +1,5 @@
 name:                syntax-pretty
-version:             0.1.0.0
+version:             0.1.0.1
 synopsis:            Syntax instance for pretty, the pretty printing library.
 license:             MIT
 license-file:        LICENSE