diff --git a/packages/field/index.vue b/packages/field/index.vue
index 342d46bbc..b14a8c6a2 100644
--- a/packages/field/index.vue
+++ b/packages/field/index.vue
@@ -115,7 +115,7 @@ export default create({
       if (this.type === 'number') {
         const { keyCode } = event;
         const allowPoint = this.value.indexOf('.') === -1;
-        const isValidKey = (keyCode >= 48 && keyCode <= 57) || (keyCode === 46 && allowPoint);
+        const isValidKey = (keyCode >= 48 && keyCode <= 57) || (keyCode === 46 && allowPoint) || keyCode === 45;
         if (!isValidKey) {
           event.preventDefault();
         }
@@ -129,6 +129,7 @@ export default create({
       }
 
       const el = this.$refs.textarea;
+      /* istanbul ignore if */
       if (!el) {
         return;
       }
diff --git a/test/specs/field.spec.js b/test/specs/field.spec.js
index 6bd97e56c..f83cc2ca2 100644
--- a/test/specs/field.spec.js
+++ b/test/specs/field.spec.js
@@ -57,12 +57,13 @@ describe('Field', () => {
   it('create a textarea field', (done) => {
     wrapper = mount(Field, {
       propsData: {
-        type: 'textarea'
+        type: 'textarea',
+        autosize: true
       }
     });
 
     setTimeout(() => {
-      expect(wrapper.hasClass('van-field--min-height')).to.be.true;
+      expect(wrapper.hasClass('van-field')).to.be.true;
       done();
     }, 50);
   });