Dont put "void" in signature for nullary functions.
diff --git a/Doc/c-api/tuple.rst b/Doc/c-api/tuple.rst
index 53db2a1..eb479d5 100644
--- a/Doc/c-api/tuple.rst
+++ b/Doc/c-api/tuple.rst
@@ -157,7 +157,7 @@
       require changes in your code for properly supporting 64-bit systems.
 
 
-.. cfunction:: int PyTuple_ClearFreeList(void)
+.. cfunction:: int PyTuple_ClearFreeList()
 
    Clear the free list. Return the total number of freed items.