diff --git a/line.py b/line.py
index 4a1e19c..1720ec6 100644
--- a/line.py
+++ b/line.py
@@ -56,7 +56,9 @@ class Line:
         return result
 
     def column_to_char(self, column_in_line: int) -> int:
-        return self._column_to_char_cache[column_in_line]
+        if column_in_line in self._column_to_char_cache:
+            return self._column_to_char_cache[column_in_line]
+        return 0
 
     def char_to_column(self, char_in_line: int) -> int:
         if not char_in_line in self._char_to_column_cache: