diff --git a/paragon.cabal b/paragon.cabal
--- a/paragon.cabal
+++ b/paragon.cabal
@@ -1,5 +1,5 @@
 Name:                   paragon
-Version:                0.1.8
+Version:                0.1.9
 License:                BSD3
 License-File:           LICENSE
 Author:                 Niklas Broberg
diff --git a/src/Language/Java/Paragon/TypeCheck.hs b/src/Language/Java/Paragon/TypeCheck.hs
--- a/src/Language/Java/Paragon/TypeCheck.hs
+++ b/src/Language/Java/Paragon/TypeCheck.hs
@@ -443,7 +443,7 @@
   --debug "typeCheckCd"
   withErrCtxt ("When checking class " ++ prettyPrint i ++ ":\n") $ do
   staticWPol <- getWritePolicy ms
-  let memberDecls = map (\(MemberDecl d) -> d) decls
+  let memberDecls = map testIt decls
   withThisType i tps $ do
   withFoldMap withTypeParam tps $ 
    typeCheckActorFields memberDecls $ do
@@ -459,6 +459,10 @@
         --debug "typeCheckMemberDecls start"
         typeCheckMemberDecls staticWPol constrWPol memberDecls
   
+
+testIt :: Decl -> MemberDecl
+testIt (MemberDecl d) = d
+testIt d = error $ "Not member decl: " ++ prettyPrint d
 
 withThisType :: Ident -> [TypeParam] -> TcCont r a -> TcCont r a
 withThisType i tps =