diff --git a/src/locales/en.js b/src/locales/en.js
index 70184142..a6f89f11 100644
--- a/src/locales/en.js
+++ b/src/locales/en.js
@@ -311,6 +311,7 @@ export default {
     'Unable to verify': 'Unable to verify',
     'Use a backup code': 'Use a backup code',
     'Use a passcode': 'Use a passcode',
+    'PIN code is invalid': 'PIN code is invalid',
     'PIN code is wrong': 'PIN code is wrong',
     'Sign Up': 'Sign Up',
     'Transaction Details': 'Transaction Details',
diff --git a/src/locales/zh_Hans.js b/src/locales/zh_Hans.js
index 90083bc1..90e4412f 100644
--- a/src/locales/zh_Hans.js
+++ b/src/locales/zh_Hans.js
@@ -311,6 +311,7 @@ export default {
     'Unable to verify': '无法验证',
     'Use a backup code': '使用备用码',
     'Use a passcode': '使用验证码',
+    'PIN code is invalid': 'PIN码无效',
     'PIN code is wrong': 'PIN码错误',
     'Sign Up': '注册',
     'Transaction Details': '交易详情',
diff --git a/src/views/mobile/ApplicationLock.vue b/src/views/mobile/ApplicationLock.vue
index afac2759..8284e7d0 100644
--- a/src/views/mobile/ApplicationLock.vue
+++ b/src/views/mobile/ApplicationLock.vue
@@ -38,7 +38,7 @@
                             <PincodeInput secure :length="6" v-model="currentPinCodeForEnable" />
                         </f7-list-item>
                     </f7-list>
-                    <f7-button large fill :class="{ 'disabled': !currentPinCodeForEnable }" :text="$t('Continue')" @click="enable(currentPinCodeForEnable)"></f7-button>
+                    <f7-button large fill :class="{ 'disabled': !currentPinCodeValid }" :text="$t('Continue')" @click="enable(currentPinCodeForEnable)"></f7-button>
                     <div class="margin-top text-align-center">
                         <f7-link @click="showInputPinCodeSheetForEnable = false" :text="$t('Cancel')"></f7-link>
                     </div>
@@ -57,6 +57,11 @@ export default {
             showInputPinCodeSheetForEnable: false
         };
     },
+    computed: {
+        currentPinCodeValid() {
+            return this.currentPinCodeForEnable && this.currentPinCodeForEnable.length === 6;
+        }
+    },
     methods: {
         enable(pinCode) {
             if (!pinCode) {
@@ -64,6 +69,11 @@ export default {
                 return;
             }
 
+            if (!this.currentPinCodeValid) {
+                this.$alert('PIN code is invalid');
+                return;
+            }
+
             this.$user.encryptToken(pinCode);
             this.$settings.setEnableApplicationLock(true);
             this.isEnableApplicationLock = true;