diff --git a/Objects/setobject.c b/Objects/setobject.c
index ebfddb3..2e62518 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -616,7 +616,7 @@
     Py_UNICODE_COPY(u, PyUnicode_AS_UNICODE(listrepr)+1,
                        newsize-2);
     u += newsize-2;
-    *u = '}';
+    *u++ = '}';
     Py_DECREF(listrepr);
 
     if (Py_TYPE(so) != &PySet_Type) {