diff --git a/mathics/eval/makeboxes.py b/mathics/eval/makeboxes.py
index 9ad27229d..d248b48a6 100644
--- a/mathics/eval/makeboxes.py
+++ b/mathics/eval/makeboxes.py
@@ -54,28 +54,36 @@ def _boxed_string(string: str, **options):
     return StyleBox(String(string), **options)
 
 
-def eval_fullform_makeboxes(self, expr, evaluation, f=SymbolStandardForm):
+def eval_fullform_makeboxes(
+    self, expr, evaluation: Evaluation, form=SymbolStandardForm
+) -> Expression:
     """
     This function takes the definitions provided by the evaluation
     object, and produces a boxed form for expr.
+
+    Basically: MakeBoxes[expr // FullForm]
     """
     # This is going to be reimplemented.
     expr = Expression(SymbolFullForm, expr)
-    return Expression(SymbolMakeBoxes, expr, f).evaluate(evaluation)
+    return Expression(SymbolMakeBoxes, expr, form).evaluate(evaluation)
 
 
-def eval_makeboxes(self, expr, evaluation, f=SymbolStandardForm):
+def eval_makeboxes(
+    self, expr, evaluation: Evaluation, form=SymbolStandardForm
+) -> Expression:
     """
     This function takes the definitions provided by the evaluation
     object, and produces a boxed fullform for expr.
+
+    Basically: MakeBoxes[expr // form]
     """
     # This is going to be reimplemented.
-    return Expression(SymbolMakeBoxes, expr, f).evaluate(evaluation)
+    return Expression(SymbolMakeBoxes, expr, form).evaluate(evaluation)
 
 
 def format_element(
     element: BaseElement, evaluation: Evaluation, form: Symbol, **kwargs
-) -> BaseElement:
+) -> Type[BaseElement]:
     """
     Applies formats associated to the expression, and then calls Makeboxes
     """
@@ -95,14 +103,14 @@ def format_element(
 
 def do_format(
     element: BaseElement, evaluation: Evaluation, form: Symbol
-) -> BaseElement:
+) -> Type[BaseElement]:
     do_format_method = element_formatters.get(type(element), do_format_element)
     return do_format_method(element, evaluation, form)
 
 
 def do_format_element(
     element: BaseElement, evaluation: Evaluation, form: Symbol
-) -> BaseElement:
+) -> Type[BaseElement]:
     """
     Applies formats associated to the expression and removes
     superfluous enclosing formats.
@@ -220,7 +228,7 @@ def format_expr(expr):
 
 def do_format_rational(
     element: BaseElement, evaluation: Evaluation, form: Symbol
-) -> BaseElement:
+) -> Type[BaseElement]:
     if form is SymbolFullForm:
         return do_format_expression(
             Expression(
@@ -245,7 +253,7 @@ def do_format_rational(
 
 def do_format_complex(
     element: BaseElement, evaluation: Evaluation, form: Symbol
-) -> BaseElement:
+) -> Type[BaseElement]:
     if form is SymbolFullForm:
         return do_format_expression(
             Expression(
@@ -273,7 +281,7 @@ def do_format_complex(
 
 def do_format_expression(
     element: BaseElement, evaluation: Evaluation, form: Symbol
-) -> BaseElement:
+) -> Type[BaseElement]:
     # # not sure how much useful is this format_cache
     # if element._format_cache is None:
     #    element._format_cache = {}