diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,4 +1,3 @@
 # Changelog for futhask
-
-## Unreleased changes
-Change in the name of the Monad from `FT` to `Fut`. This is a breaking change, but in principle a simple search and replace should fix it. The motivation for the change is both that it is more descriptive, and the introduction of the transformer. `FutT` simply looks better then `FTT`, especially in names using CamelCase. The original name `FT` was inspired by `ST`, since they both use rigid type variables for similar purposes.
+## 1.1.0
+fix bugs in sum type handling
diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -81,8 +81,8 @@
     T.writeFile (natdir <> "Types.hs") $ nativeTypes
     T.writeFile (unpdir <> "Types.hs") $ unpackedTypes
     where
-        futhaskVersion = "1.0.0.0"
-        futhaskBaseVersion = "0.1.0.0"
+        futhaskVersion = "1.1.0.0"
+        futhaskBaseVersion = "0.2.0.0"
         --name = "testlib"
         --libver = "0.1"
         --pacdir = "../testlibrary/"
diff --git a/futhask.cabal b/futhask.cabal
--- a/futhask.cabal
+++ b/futhask.cabal
@@ -1,7 +1,7 @@
 cabal-version: 1.12
 
 name:           futhask
-version:        1.0.0
+version:        1.1.0
 synopsis:       Generate Haskell wrappers for Futhark libraries
 description:    Please see the README on GitLab at <https://gitlab.com/Gusten_Isfeldt/futhask#futhask>
 category:       FFI Tools
diff --git a/src/CodeGen.hs b/src/CodeGen.hs
--- a/src/CodeGen.hs
+++ b/src/CodeGen.hs
@@ -160,7 +160,7 @@
     "Tup" <> T.pack (show (length fields)) <-> T.intercalate "_" (map formatCompositeType fields)
 formatCompositeType (RecordType fields) =
     "Rec" <> T.pack (show (length fields)) <-> T.intercalate "_" (map (\(n, t) -> T.pack n <-> formatCompositeType t) fields)
-formatCompositeType (SumType variants) = "Sum" <> T.pack (show (length variants)) <-> T.intercalate "_" (map (\(c, ps) -> T.pack c <-> T.intercalate "_" (map formatCompositeType ps)) variants) 
+formatCompositeType (SumType variants) = "Sum" <> T.pack (show (length variants)) <-> T.intercalate "_" (map (\(c, ps) -> T.intercalate "_" (T.pack c : map formatCompositeType ps)) variants) 
 
 haskellEquivType :: CompositeType -> Text
 haskellEquivType (SimpleType t) = haskellType t
@@ -203,9 +203,10 @@
             >>= \m -> char '}' >> pure (RecordType m)
         '[' -> P.munch (\c -> elem c ("[]" :: String)) >>= \p -> readCompositeType >>= \elem -> pure (ArrayType (div (length p + 1) 2) elem) 
         '#' -> P.sepBy 
-            (P.munch (/=' ') >>= \cons -> P.sepBy readCompositeType (P.char ' ') >>= \payloads -> pure (cons, payloads)) 
+            (P.munch (\c -> not $ elem c (" ,"::String)) >>= \cons -> P.sepBy readCompositeType (P.char ' ') >>= \payloads -> pure (cons, payloads)) 
             (P.string " | #")
-            >>= \cps -> pure (SumType cps) 
+            >>= \cps -> pure (SumType cps)
+        ',' -> P.pfail
         _   -> P.munch (\c -> not $ elem c (" ()[]{},#|"::String)) >>= \cs -> pure (SimpleType (T.pack (c:cs)))
     where
         char c = P.char c >>= \_ -> pure ()