#4682: 'b' is actually unsigned char.
diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst
index 5dc28af..c3da859 100644
--- a/Doc/c-api/arg.rst
+++ b/Doc/c-api/arg.rst
@@ -136,8 +136,9 @@
them. Instead, the implementation assumes that the string object uses the
encoding passed in as parameter.
-``b`` (integer) [char]
- Convert a Python integer to a tiny int, stored in a C :ctype:`char`.
+``b`` (integer) [unsigned char]
+ Convert a nonnegative Python integer to an unsigned tiny int, stored in a C
+ :ctype:`unsigned char`.
``B`` (integer) [unsigned char]
Convert a Python integer to a tiny int without overflow checking, stored in a C