diff --git a/packages/babel-traverse/src/path/family.js b/packages/babel-traverse/src/path/family.js
index 6ef3f4535cb6..0af3d2b110cb 100644
--- a/packages/babel-traverse/src/path/family.js
+++ b/packages/babel-traverse/src/path/family.js
@@ -1,3 +1,4 @@
+// @flow
 // This file contains methods responsible for dealing with/retrieving children or siblings.
 
 import type TraversalContext from "../index";
@@ -17,7 +18,7 @@ function addCompletionRecords(path, paths) {
   return paths;
 }
 
-export function getCompletionRecords(): Array {
+export function getCompletionRecords(): NodePath[] {
   let paths = [];
 
   if (this.isIfStatement()) {
@@ -42,7 +43,7 @@ export function getCompletionRecords(): Array {
   return paths;
 }
 
-export function getSibling(key): NodePath {
+export function getSibling(key: string): NodePath {
   return NodePath.get({
     parentPath: this.parentPath,
     parent: this.parent,
@@ -60,10 +61,10 @@ export function getNextSibling(): NodePath {
   return this.getSibling(this.key + 1);
 }
 
-export function getAllNextSiblings(): Array<NodePath> {
+export function getAllNextSiblings(): NodePath[] {
   let _key = this.key;
-  let sibling: NodePath = this.getSibling(++_key);
-  const siblings: Array<NodePath> = [];
+  let sibling = this.getSibling(++_key);
+  const siblings = [];
   while (sibling.node) {
     siblings.push(sibling);
     sibling = this.getSibling(++_key);
@@ -71,10 +72,10 @@ export function getAllNextSiblings(): Array<NodePath> {
   return siblings;
 }
 
-export function getAllPrevSiblings(): Array<NodePath> {
+export function getAllPrevSiblings(): NodePath[] {
   let _key = this.key;
-  let sibling: NodePath = this.getSibling(--_key);
-  const siblings: Array<NodePath> = [];
+  let sibling = this.getSibling(--_key);
+  const siblings = [];
   while (sibling.node) {
     siblings.push(sibling);
     sibling = this.getSibling(--_key);
@@ -85,7 +86,7 @@ export function getAllPrevSiblings(): Array<NodePath> {
 export function get(
   key: string,
   context?: boolean | TraversalContext,
-): NodePath {
+): NodePath | NodePath[] {
   if (context === true) context = this.context;
   const parts = key.split(".");
   if (parts.length === 1) {
@@ -97,7 +98,10 @@ export function get(
   }
 }
 
-export function _getKey(key, context?) {
+export function _getKey(
+  key: string,
+  context?: TraversalContext,
+): NodePath | NodePath[] {
   const node = this.node;
   const container = node[key];
 
@@ -122,9 +126,12 @@ export function _getKey(key, context?) {
   }
 }
 
-export function _getPattern(parts, context) {
+export function _getPattern(
+  parts: string[],
+  context?: TraversalContext,
+): NodePath | NodePath[] {
   let path = this;
-  for (const part of (parts: Array)) {
+  for (const part of parts) {
     if (part === ".") {
       path = path.parentPath;
     } else {
@@ -138,11 +145,11 @@ export function _getPattern(parts, context) {
   return path;
 }
 
-export function getBindingIdentifiers(duplicates?): Object {
+export function getBindingIdentifiers(duplicates?: boolean): Object {
   return t.getBindingIdentifiers(this.node, duplicates);
 }
 
-export function getOuterBindingIdentifiers(duplicates?): Object {
+export function getOuterBindingIdentifiers(duplicates?: boolean): Object {
   return t.getOuterBindingIdentifiers(this.node, duplicates);
 }
 
@@ -150,9 +157,9 @@ export function getOuterBindingIdentifiers(duplicates?): Object {
 // path.getBindingIdentifiers returns nodes where the following re-implementation
 // returns paths
 export function getBindingIdentifierPaths(
-  duplicates = false,
-  outerOnly = false,
-) {
+  duplicates?: boolean = false,
+  outerOnly?: boolean = false,
+): { [string]: NodePath } {
   const path = this;
   let search = [].concat(path);
   const ids = Object.create(null);
@@ -203,9 +210,12 @@ export function getBindingIdentifierPaths(
     }
   }
 
+  // $FlowIssue Object.create() is object type
   return ids;
 }
 
-export function getOuterBindingIdentifierPaths(duplicates?) {
+export function getOuterBindingIdentifierPaths(
+  duplicates?: boolean,
+): { [string]: NodePath } {
   return this.getBindingIdentifierPaths(duplicates, true);
 }