diff --git a/examples/features/Param.gf b/examples/features/Param.gf
new file mode 100644
index 000000000..0b5ed2453
--- /dev/null
+++ b/examples/features/Param.gf
@@ -0,0 +1,10 @@
+resource Param = {
+
+  param Bool = True | False ;
+
+  oper and : Bool -> Bool -> Bool = \x,y -> case x of {
+    True => y ;
+    _ => False
+    } ;
+
+}
diff --git a/src/GF/Devel/Compile/CheckGrammar.hs b/src/GF/Devel/Compile/CheckGrammar.hs
index 831d0b9b2..1baab392f 100644
--- a/src/GF/Devel/Compile/CheckGrammar.hs
+++ b/src/GF/Devel/Compile/CheckGrammar.hs
@@ -516,6 +516,8 @@ inferLType gr trm = case trm of
 
    Empty -> return (trm, typeStr)
 
+   EParam _ cos -> return (trm, typePType) ---- check cos
+
    C s1 s2 -> 
      check2 (flip justCheck typeStr) C s1 s2 typeStr
 
diff --git a/src/GF/Devel/Grammar/Construct.hs b/src/GF/Devel/Grammar/Construct.hs
index bd480cbe1..eb4ce857d 100644
--- a/src/GF/Devel/Grammar/Construct.hs
+++ b/src/GF/Devel/Grammar/Construct.hs
@@ -114,7 +114,7 @@ resOverload tts = resOperDef (Overload tts)
 -- param p = ci gi  is encoded as p : ((ci : gi) -> p) -> Type
 -- we use EData instead of p to make circularity check easier  
 resParam :: Ident -> [(Ident,Context)] -> Judgement
-resParam p cos = addJDef (EParam cos) (emptyJudgement JParam)
+resParam p cos = addJDef (EParam (Con p) cos) (addJType typePType (emptyJudgement JParam))
 
 -- to enable constructor type lookup:
 -- create an oper for each constructor p = c g, as c : g -> p = EData
diff --git a/src/GF/Devel/Grammar/GFtoSource.hs b/src/GF/Devel/Grammar/GFtoSource.hs
index 318974f5d..292f5b826 100644
--- a/src/GF/Devel/Grammar/GFtoSource.hs
+++ b/src/GF/Devel/Grammar/GFtoSource.hs
@@ -71,7 +71,7 @@ trAnyDef (i,ju) = let
   ----  JFun ty EData -> [P.DefFunData [P.FunDef [i'] (trt ty)]]
   JParam -> [P.DefPar [
     P.ParDefDir i0 [
-      P.ParConstr (tri c) (map trDecl co) | let EParam cos = jdef ju, (c,co) <- cos]
+      P.ParConstr (tri c) (map trDecl co) | let EParam _ cos = jdef ju, (c,co) <- cos]
     ]] 
   JOper -> case jdef ju of 
     Overload tysts -> 
@@ -160,6 +160,8 @@ trt trm = case trm of
     Alts (t, tt) -> P.EPre (trt t) [P.Alt (trt v) (trt c) | (v,c) <- tt]
     FV ts -> P.EVariants $ map trt ts
     EData -> P.EData
+    EParam t _ -> trt t
+
     _ -> error $ "not yet" +++ show trm ----
 
 trp :: Patt -> P.Patt
diff --git a/src/GF/Devel/Grammar/Grammar.hs b/src/GF/Devel/Grammar/Grammar.hs
index 600f74095..374d9b2f2 100644
--- a/src/GF/Devel/Grammar/Grammar.hs
+++ b/src/GF/Devel/Grammar/Grammar.hs
@@ -109,7 +109,7 @@ data Term =
  | EPatt Patt
  | EPattType Term
 
- | EParam [(Ident,Context)] -- to encode parameter constructor sets
+ | EParam Term [(Ident,Context)] -- to encode parameter constructor sets
 
  | FV [Term]            -- ^ free variation: @variants { s ; ... }@
 
diff --git a/src/GF/Devel/Grammar/Lookup.hs b/src/GF/Devel/Grammar/Lookup.hs
index 0d2b343cb..0a8452dcb 100644
--- a/src/GF/Devel/Grammar/Lookup.hs
+++ b/src/GF/Devel/Grammar/Lookup.hs
@@ -61,20 +61,16 @@ lookupOverload gr m c = do
 
 lookupParams :: GF -> Ident -> Ident -> Err [(Ident,Context)]
 lookupParams gf m c = do
-  ty <- lookupJField jtype gf m c
-  return [(k,contextOfType t) | (k,t) <- contextOfType ty]
+  EParam _ ty <- lookupJField jdef gf m c
+  return ty
 
 lookupParamConstructor :: GF -> Ident -> Ident -> Err Type
 lookupParamConstructor = lookupJField jtype
 
 lookupParamValues :: GF -> Ident -> Ident -> Err [Term]
 lookupParamValues gf m c = do
-  d <- lookupJField jdef gf m c
-  case d of
-    ---- V _ ts -> return ts
-    _ -> do
-      ps <- lookupParams gf m c
-      liftM concat $ mapM mkPar ps
+  ps <- lookupParams gf m c
+  liftM concat $ mapM mkPar ps
  where
    mkPar (f,co) = do
      vs <- liftM combinations $ mapM (\ (_,ty) -> allParamValues gf ty) co
diff --git a/src/GF/Devel/Grammar/Macros.hs b/src/GF/Devel/Grammar/Macros.hs
index f08c28a0b..1a7a3582c 100644
--- a/src/GF/Devel/Grammar/Macros.hs
+++ b/src/GF/Devel/Grammar/Macros.hs
@@ -259,9 +259,10 @@ composOp co trm = case trm of
    Eqs cc -> 
      do cc' <- mapPairListM (co . snd) cc
         return (Eqs cc')
-   EParam cos -> 
-     do cos' <- mapPairListM (mapPairListM (co . snd) . snd) cos
-        return (EParam cos')
+   EParam ty cos -> 
+     do ty' <- co ty
+        cos' <- mapPairListM (mapPairListM (co . snd) . snd) cos
+        return (EParam ty' cos')
    V ty vs ->
      do ty' <- co ty
         vs' <- mapM co vs