diff --git a/src/fsharp/ilxgen.fs b/src/fsharp/ilxgen.fs
index b7b016a7b4b6ce02f289c4189ae4382afe8a880e..a14f39593fb33d2a3193b410294fb94b63fe5215 100644
--- a/src/fsharp/ilxgen.fs
+++ b/src/fsharp/ilxgen.fs
@@ -3956,7 +3956,7 @@ and GetIlxClosureInfo cenv m isLocalTypeFunc  selfv eenvouter expr =
         let rec getCallStructure tvacc vacc (e,ety) = 
             match e with 
             | Expr.TyLambda(_,tvs,body,_m,bty) -> 
-                getCallStructure (tvs :: tvacc) vacc (body,bty)
+                getCallStructure ((DropErasedTypars tvs) :: tvacc) vacc (body,bty)
             | Expr.Lambda (_,_,_,vs,body,_,bty) when not isLocalTypeFunc -> 
                 // Transform a lambda taking untupled arguments into one 
                 // taking only a single tupled argument if necessary.  REVIEW: do this earlier