diff --git a/dist/mixins/observer/index.js b/dist/mixins/observer/index.js
index 487f2a48..c74a6c37 100644
--- a/dist/mixins/observer/index.js
+++ b/dist/mixins/observer/index.js
@@ -10,7 +10,7 @@ export function observe(vantOptions, options) {
       if (key in props) {
         var prop = props[key];
 
-        if (prop === null || !prop.type) {
+        if (prop === null || !('type' in prop)) {
           prop = {
             type: prop
           };
diff --git a/dist/mixins/observer/props.js b/dist/mixins/observer/props.js
index 254cfffd..4d71776f 100644
--- a/dist/mixins/observer/props.js
+++ b/dist/mixins/observer/props.js
@@ -6,7 +6,7 @@ export function observeProps(props) {
   Object.keys(props).forEach(function (key) {
     var prop = props[key];
 
-    if (prop === null || !prop.type) {
+    if (prop === null || !('type' in prop)) {
       prop = {
         type: prop
       };
diff --git a/dist/tabs/index.js b/dist/tabs/index.js
index d59870d4..94cc1994 100644
--- a/dist/tabs/index.js
+++ b/dist/tabs/index.js
@@ -25,7 +25,7 @@ VantComponent({
     color: String,
     lineWidth: Number,
     active: {
-      type: null,
+      type: Number,
       value: 0
     },
     type: {
@@ -139,7 +139,7 @@ VantComponent({
       this.scrollIntoView();
     },
     // scroll active tab into view
-    scrollIntoView: function scrollIntoView(immediate) {
+    scrollIntoView: function scrollIntoView() {
       var _this3 = this;
 
       if (!this.data.scrollable) {
diff --git a/packages/mixins/observer/index.ts b/packages/mixins/observer/index.ts
index 9a689626..fe871de7 100644
--- a/packages/mixins/observer/index.ts
+++ b/packages/mixins/observer/index.ts
@@ -9,7 +9,7 @@ export function observe(vantOptions, options) {
     Object.keys(watch).forEach(key => {
       if (key in props) {
         let prop = props[key];
-        if (prop === null || !prop.type) {
+        if (prop === null || !('type' in prop)) {
           prop = { type: prop };
         }
         prop.observer = watch[key];
diff --git a/packages/mixins/observer/props.ts b/packages/mixins/observer/props.ts
index 9f7923f6..fdc193f6 100644
--- a/packages/mixins/observer/props.ts
+++ b/packages/mixins/observer/props.ts
@@ -5,7 +5,7 @@ export function observeProps(props) {
 
   Object.keys(props).forEach(key => {
     let prop = props[key];
-    if (prop === null || !prop.type) {
+    if (prop === null || !('type' in prop)) {
       prop = { type: prop };
     }
 
diff --git a/packages/tab/README.md b/packages/tab/README.md
index 395ee00d..323de4d2 100644
--- a/packages/tab/README.md
+++ b/packages/tab/README.md
@@ -115,7 +115,7 @@ Page({
 
 | 参数 | 说明 | 类型 | 默认值 |
 |-----------|-----------|-----------|-------------|
-| active | 当前激活标签的索引 | `String` `Number` | `0` |
+| active | 当前激活标签的索引 | `Number` | `0` |
 | color | 标签颜色 | `String` | `#f44` |
 | type | 样式风格，可选值为`card` | `String` | `line` |
 | border | 是否展示外边框，仅在`line`风格下生效 | `Boolean` | `true` |
diff --git a/packages/tabs/index.ts b/packages/tabs/index.ts
index f48e7689..1bd110c6 100644
--- a/packages/tabs/index.ts
+++ b/packages/tabs/index.ts
@@ -30,7 +30,7 @@ VantComponent({
     color: String,
     lineWidth: Number,
     active: {
-      type: null,
+      type: Number,
       value: 0
     },
     type: {
@@ -84,7 +84,7 @@ VantComponent({
       this.setActiveTab();
     },
 
-    trigger(eventName, index) {
+    trigger(eventName: string, index: number) {
       this.$emit(eventName, {
         index,
         title: this.data.tabs[index].data.title
@@ -101,7 +101,7 @@ VantComponent({
       }
     },
 
-    setActive(active) {
+    setActive(active: number) {
       if (active !== this.data.active) {
         this.trigger('change', active);
         this.setData({ active });
@@ -153,7 +153,7 @@ VantComponent({
     },
 
     // scroll active tab into view
-    scrollIntoView(immediate) {
+    scrollIntoView() {
       if (!this.data.scrollable) {
         return;
       }