diff --git a/src/attr/_make.py b/src/attr/_make.py
index 6cfbc250..63f598f0 100644
--- a/src/attr/_make.py
+++ b/src/attr/_make.py
@@ -3036,6 +3036,11 @@ def _get_global_name(attr_name: str) -> str:
         return f"__attr_converter_{attr_name}"
 
     def _fmt_converter_call(self, attr_name: str, value_var: str) -> str:
+        """
+        Return a string that calls the converter for an attribute name
+        *attr_name* and the value in variable named *value_var* according to
+        `self.takes_self` and `self.takes_field`.
+        """
         if not (self.takes_self or self.takes_field):
             return f"{self._get_global_name(attr_name)}({value_var})"