--- a/Parser/node.c
+++ b/Parser/node.c
@@ -91,6 +91,9 @@
 	if (current_capacity < 0 || required_capacity < 0)
 		return E_OVERFLOW;
 	if (current_capacity < required_capacity) {
+		if (required_capacity > PY_SIZE_MAX / sizeof(node)) {
+			return E_NOMEM;
+		}
 		n = n1->n_child;
 		n = (node *) PyObject_REALLOC(n,
 					      required_capacity * sizeof(node));