diff --git a/common/Types.hs b/common/Types.hs
index b0e97c0..1b0926d 100644
--- a/common/Types.hs
+++ b/common/Types.hs
@@ -99,6 +99,20 @@ typeOfSpec' st
             A.IsExpr a b t c -> return $ Just (t, \t' -> A.IsExpr a b t' c)
             A.IsChannelArray a t b
               -> return $ Just (t, \t' -> A.IsChannelArray a t' b)
+            A.IsClaimed m v
+              -> do t <- typeOfVariable v
+                    let t' = case t of
+                          A.Chan attr innerT -> Just $ A.Chan (attr
+                            { A.caWritingShared = A.Unshared
+                            , A.caReadingShared = A.Unshared
+                            }) innerT
+                          A.ChanEnd A.DirInput _ innerT
+                            -> Just $ A.ChanEnd A.DirInput A.Unshared innerT
+                          A.ChanEnd A.DirOutput _ innerT
+                            -> Just $ A.ChanEnd A.DirOutput A.Unshared innerT
+                          A.ChanDataType dir _ innerT -> Just $ A.ChanDataType dir A.Unshared innerT
+                          _ -> Nothing
+                    return $ fmap (\x -> (x, error "typeOfSpec'")) t'
             A.Retypes a b t c -> return $ Just (t, \t' -> A.Retypes a b t' c)
             A.RetypesExpr a b t c
               -> return $ Just (t, \t' -> A.RetypesExpr a b t' c)
diff --git a/frontends/OccamTypes.hs b/frontends/OccamTypes.hs
index 41b4a42..739f27a 100644
--- a/frontends/OccamTypes.hs
+++ b/frontends/OccamTypes.hs
@@ -1331,6 +1331,12 @@ checkSpecTypes = checkDepthM doSpecType
               checkType (findMeta e) t te
               checkValAM m am
               checkAbbrev m A.ValAbbrev am
+    doSpecType (A.IsClaimed m v)
+        =  do t <- astTypeOf v
+              case t of
+                A.ChanEnd _ A.Shared _ -> return ()
+                A.ChanDataType _ A.Shared _ -> return ()
+                _ -> dieP m "Expected shared channel end in claim"
     doSpecType (A.IsChannelArray m rawT cs)
         =  do t <- resolveUserType m rawT
               let isChan (A.Chan {}) = True