diff --git a/src/Serializing/Format.hs b/src/Serializing/Format.hs
index d897a24e9..bc5b716ba 100644
--- a/src/Serializing/Format.hs
+++ b/src/Serializing/Format.hs
@@ -7,14 +7,18 @@ module Serializing.Format
 
 import Algebra.Graph.Class
 import Data.ByteString.Builder
+import Prologue
 import Serializing.DOT
+import Serializing.SExpression
 
 data Format input where
-  DOT  :: (Ord vertex, ToGraph graph, ToVertex graph ~ vertex) => Style vertex Builder -> Format graph
-  Show :: Show input                                                                   => Format input
+  DOT         :: (Ord vertex, ToGraph graph, ToVertex graph ~ vertex) => Style vertex Builder -> Format graph
+  SExpression :: (Recursive input, ToSExpression (Base input))                                => Format input
+  Show        :: Show input                                                                   => Format input
 
 runSerialize :: Format input -> input -> Builder
 runSerialize (DOT style) graph = serializeDOT style graph
+runSerialize SExpression input = serializeSExpression input
 runSerialize Show        input = stringUtf8 (show input)
 
 -- TODO: it would be kinda neat if we could use pretty-show/hscolour for Show output