diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index 4d2a8e4..477f526 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -595,7 +595,7 @@
 
 /* Convert the Unicode object to a wide character string. The output string
    always ends with a nul character. If size is not NULL, write the number of
-   wide characters (including the nul character) into *size.
+   wide characters (excluding the null character) into *size.
 
    Returns a buffer allocated by PyMem_Alloc() (use PyMem_Free() to free it)
    on success. On error, returns NULL, *size is undefined and raises a