diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 94f290853cc..6306c3ac564 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -2431,6 +2431,11 @@ builtin_sum_impl(PyObject *module, PyObject *iterable, PyObject *start)
                 }
             }
             result = PyFloat_FromDouble(f_result);
+            if (result == NULL) {
+                Py_DECREF(item);
+                Py_DECREF(iter);
+                return NULL;
+            }
             temp = PyNumber_Add(result, item);
             Py_DECREF(result);
             Py_DECREF(item);