diff --git a/Python/compile.c b/Python/compile.c
index 9ce8ac3..94a2715 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -1551,6 +1551,7 @@
 	{
 		/* use the class name for name mangling */
 		Py_INCREF(s->v.ClassDef.name);
+		Py_XDECREF(c->u->u_private);
 		c->u->u_private = s->v.ClassDef.name;
 		/* force it to have one mandatory argument */
 		c->u->u_argcount = 1;