diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 91be603..99069cd 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -3100,9 +3100,9 @@
     return v;
 }
 
-/* Normalize an encoding name: C implementation of
-   encodings.normalize_encoding(). Return 1 on success, or 0 on error (encoding
-   is longer than lower_len-1). */
+/* Normalize an encoding name: similar to encodings.normalize_encoding(), but
+   also convert to lowercase. Return 1 on success, or 0 on error (encoding is
+   longer than lower_len-1). */
 int
 _Py_normalize_encoding(const char *encoding,
                        char *lower,