diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 6a6f8cf7392..c2b8283d84e 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -3538,7 +3538,8 @@ PyDoc_STRVAR(getsockname_doc,
 \n\
 Return the address of the local endpoint. The format depends on the\n\
 address family. For IPv4 sockets, the address info is a pair\n\
-(hostaddr, port).");
+(hostaddr, port). For IPv6 sockets, the address info is a 4-tuple\n\
+(hostaddr, port, flowinfo, scope_id).");
 #endif