diff --git a/lib/src/prelude/Predef.gf b/lib/src/prelude/Predef.gf
index b4dcbc5e9..86138db1b 100644
--- a/lib/src/prelude/Predef.gf
+++ b/lib/src/prelude/Predef.gf
@@ -13,7 +13,7 @@ resource Predef = {
 
   oper Error : Type = variants {} ;          -- the empty type
   oper Int   : Type = variants {} ;          -- the type of integers
-  oper Ints  : Int -> Type = variants {} ;   -- the type of integers from 0 to n
+  oper Ints  : Int -> PType = variants {} ;  -- the type of integers from 0 to n
 
   oper error  : Str        -> Error    = variants {} ; -- forms error message
   oper length : Tok ->        Int      = variants {} ; -- length of string