diff --git a/Include/internal/pycore_pylifecycle.h b/Include/internal/pycore_pylifecycle.h
index b0adc4562c4..b76bb2c7778 100644
--- a/Include/internal/pycore_pylifecycle.h
+++ b/Include/internal/pycore_pylifecycle.h
@@ -82,7 +82,7 @@ extern void _PyFaulthandler_Fini(void);
 extern void _PyHash_Fini(void);
 extern void _PyTraceMalloc_Fini(void);
 extern void _PyWarnings_Fini(PyInterpreterState *interp);
-extern void _PyAST_Fini();
+extern void _PyAST_Fini(void);
 
 extern PyStatus _PyGILState_Init(PyThreadState *tstate);
 extern void _PyGILState_Fini(PyThreadState *tstate);