diff --git a/fpco-api.cabal b/fpco-api.cabal
--- a/fpco-api.cabal
+++ b/fpco-api.cabal
@@ -1,5 +1,5 @@
 name:                 fpco-api
-version:              1.1.1.3
+version:              1.1.1.4
 synopsis:             Simple interface to the FP Complete IDE API.
 description:          A server and library for communicating with the FP Complete IDE API.
 homepage:             https://www.fpcomplete.com/page/api
@@ -55,6 +55,7 @@
                       http-types >=0.8,
                       persistent >=1.2,
                       persistent-template >=1.2,
+                      tagged,
                       random >=1.0
 
 executable fpco-api
diff --git a/src/library/FP/API/Types.hs b/src/library/FP/API/Types.hs
--- a/src/library/FP/API/Types.hs
+++ b/src/library/FP/API/Types.hs
@@ -11,6 +11,7 @@
 import Language.Fay.Yesod
 import Prelude
 import FFI
+import Data.Proxy
 
 #ifndef FAY
 import Data.Default (Default(..))