diff --git a/src/FWL/Compile.hs b/src/FWL/Compile.hs
index 0fa206a..f4043c1 100644
--- a/src/FWL/Compile.hs
+++ b/src/FWL/Compile.hs
@@ -257,9 +257,15 @@ renderNftType [t] = A.String (toText t)
 renderNftType ts  = toJSON ts
 
 exprToVal :: Expr -> Value
-exprToVal (ELit (LPort p)) = toJSON p
-exprToVal (ELit (LInt n))  = toJSON n
-exprToVal (ELit l)         = A.String (toText (renderLit l))
+exprToVal (ELit (LPort p))   = toJSON p
+exprToVal (ELit (LInt n))    = toJSON n
+exprToVal (ELit (LCIDR ip p))= object
+  [ "prefix" .= object
+      [ "addr" .= A.String (toText (renderLit ip))
+      , "len"  .= p
+      ]
+  ]
+exprToVal (ELit l)           = A.String (toText (renderLit l))
 exprToVal (EVar n)         = A.String (toText n)
 exprToVal (EQual ns)       = A.String (toText (intercalate "." ns))
 exprToVal _                = A.String "_"