src/Tools/code/code_haskell.ML

           |> map NameSpace.base
           |> has_duplicates (op =);
         val imports = deps'
           |> map NameSpace.qualifier
           |> distinct (op =);
-        fun pr_import_include (name, _) = str ("import " ^ name ^ ";");
+        fun pr_import_include (name, _) = str ("import qualified " ^ name ^ ";");
         val pr_import_module = str o (if qualified
           then prefix "import qualified "
           else prefix "import ") o suffix ";";
         val content = Pretty.chunks (
             map pr_import_include includes