| dopt Opt_DoLambdaEtaExpansion dflags,
not (inGentleMode env), -- In gentle mode don't eta-expansion
- any isRuntimeVar bndrs -- because it can clutter up the code
+ -- because it can clutter up the code
-- with casts etc that may not be removed
+ not (all isTyVar bndrs) -- Don't eta expand type abstractions
= do { let body' = tryEtaExpansion dflags body
; return (mkLams bndrs body') }