diff --git a/mapytex/calculus/core/renders/tree2tex.py b/mapytex/calculus/core/renders/tree2tex.py
index 840fd81..3b24f18 100644
--- a/mapytex/calculus/core/renders/tree2tex.py
+++ b/mapytex/calculus/core/renders/tree2tex.py
@@ -196,7 +196,10 @@ def render_with_parenthesis(subtree, operator):
                 subtree_need_parenthesis = True
         except (AttributeError, KeyError):
             pass
-        subtree_ = subtree.__tex__
+        try:
+            subtree_ = subtree.__txt__
+        except AttributeError:
+            subtree_ = subtree
     else:
         if OPERATORS[subtree.node]["precedence"] < OPERATORS[operator]["precedence"]:
             subtree_need_parenthesis = True
diff --git a/mapytex/calculus/core/renders/tree2txt.py b/mapytex/calculus/core/renders/tree2txt.py
index a58cc62..d6c36c3 100644
--- a/mapytex/calculus/core/renders/tree2txt.py
+++ b/mapytex/calculus/core/renders/tree2txt.py
@@ -200,7 +200,10 @@ def render_with_parenthesis(subtree, operator):
                 subtree_need_parenthesis = True
         except (AttributeError, KeyError):
             pass
-        subtree_ = subtree.__txt__
+        try:
+            subtree_ = subtree.__txt__
+        except AttributeError:
+            subtree_ = subtree
     else:
         if OPERATORS[subtree.node]["precedence"] < OPERATORS[operator]["precedence"]:
             subtree_need_parenthesis = True