diff --git a/packages/babel-types/src/traverse/traverseFast.js b/packages/babel-types/src/traverse/traverseFast.js
index 1db6a81cb2c2..306daa8d9c2a 100644
--- a/packages/babel-types/src/traverse/traverseFast.js
+++ b/packages/babel-types/src/traverse/traverseFast.js
@@ -1,10 +1,14 @@
 // @flow
 import { VISITOR_KEYS } from "../definitions";
-import type { Node } from "@babel/types";
+
+// This workaround is needed because BabelNode doesn't have a "type" property,
+// which is only defined by its subclasses.
+type _Node<T: BabelNode & { type: string }> = T;
+type Node = _Node<*>;
 
 opaque type Stop = Symbol;
 
-type EnterCallback = (node: Node, opts: ?Object, parent: ?Node) => Stop | void;
+type EnterCallback = (node: Node, opts?: Object, parent?: Node) => Stop | void;
 
 type TraverseFast = {
   (node: Node, enter: EnterCallback, opts?: Object): void,