diff --git a/src/core/instance/inject.js b/src/core/instance/inject.js
index 019026479ec..cb14cfeb05d 100644
--- a/src/core/instance/inject.js
+++ b/src/core/instance/inject.js
@@ -3,6 +3,7 @@
 import { warn } from '../util/index'
 import { hasSymbol } from 'core/util/env'
 import { defineReactive, observerState } from '../observer/index'
+import { hasOwn } from 'shared/util'
 
 export function initProvide (vm: Component) {
   const provide = vm.$options.provide
@@ -52,7 +53,7 @@ export function resolveInject (inject: any, vm: Component): ?Object {
       const provideKey = inject[key].from
       let source = vm
       while (source) {
-        if (source._provided && provideKey in source._provided) {
+        if (source._provided && hasOwn(source._provided, provideKey)) {
           result[key] = source._provided[provideKey]
           break
         }
diff --git a/test/unit/features/options/inject.spec.js b/test/unit/features/options/inject.spec.js
index cd5c7097f31..53f55e1ecf2 100644
--- a/test/unit/features/options/inject.spec.js
+++ b/test/unit/features/options/inject.spec.js
@@ -635,4 +635,16 @@ describe('Options provide/inject', () => {
 
     expect(injected).toEqual('foo')
   })
+
+  // #7284
+  it('should not inject prototype properties', () => {
+    const vm = new Vue({
+      provide: {}
+    })
+    new Vue({
+      parent: vm,
+      inject: ['constructor']
+    })
+    expect(`Injection "constructor" not found`).toHaveBeenWarned()
+  })
 })