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:              1.0.4
+version:              1.0.5
 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
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
@@ -554,7 +554,11 @@
 -- Isolation-runner ids
 
 data CompileId = CompileId { unCompileId :: Int }
-    deriving (Read, Typeable, Data, Show, Eq)
+    deriving (Read, Typeable, Data, Show, Eq
+#ifndef FAY
+    , Ord
+#endif
+    )
 
 data ProcId = ProcId { unProcId :: Int }
     deriving (Read, Typeable, Data, Show, Eq)