diff --git a/src/ui/bigtext/bigtext.py b/src/ui/bigtext/bigtext.py
index a962c4e..82ca356 100644
--- a/src/ui/bigtext/bigtext.py
+++ b/src/ui/bigtext/bigtext.py
@@ -391,8 +391,8 @@ class InnerBigText(QWidget):
         self.update()
 
     def _update_highlight_selected_text(self):
-        start_byte=self.selection_highlight.start_byte
-        end_byte=self.selection_highlight.end_byte
+        start_byte = min(self.selection_highlight.start_byte, self.selection_highlight.end_byte)
+        end_byte = max(self.selection_highlight.start_byte, self.selection_highlight.end_byte)
         if abs(start_byte - end_byte) < 1024:
             query = self.model.read_range(start_byte, end_byte)
             if query.find("\n") < 0: