diff --git a/src/utils.ts b/src/utils.ts
index 2748805c7..68391a950 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -14,6 +14,26 @@ function mergeStubs(target: Record<string, any>, source: GlobalMountOptions) {
   }
 }
 
+// perform 1-level-deep-pseudo-clone merge in order to prevent config leaks
+// example: vue-router overwrites globalProperties.$router
+function mergeAppConfig(
+  configGlobalConfig: GlobalMountOptions['config'],
+  mountGlobalConfig: GlobalMountOptions['config']
+): Required<GlobalMountOptions>['config'] {
+  return {
+    ...configGlobalConfig,
+    ...mountGlobalConfig,
+    globalProperties: {
+      ...configGlobalConfig?.globalProperties,
+      ...mountGlobalConfig?.globalProperties
+    },
+    compilerOptions: {
+      ...configGlobalConfig?.compilerOptions,
+      ...mountGlobalConfig?.compilerOptions
+    }
+  }
+}
+
 export function mergeGlobalProperties(
   mountGlobal: GlobalMountOptions = {}
 ): Required<GlobalMountOptions> {
@@ -34,7 +54,7 @@ export function mergeGlobalProperties(
     components: { ...configGlobal.components, ...mountGlobal.components },
     provide: { ...configGlobal.provide, ...mountGlobal.provide },
     mocks: { ...configGlobal.mocks, ...mountGlobal.mocks },
-    config: { ...configGlobal.config, ...mountGlobal.config },
+    config: mergeAppConfig(configGlobal.config, mountGlobal.config),
     directives: { ...configGlobal.directives, ...mountGlobal.directives },
     renderStubDefaultSlot
   }
diff --git a/tests/config.spec.ts b/tests/config.spec.ts
index d292bf151..a18adb27d 100644
--- a/tests/config.spec.ts
+++ b/tests/config.spec.ts
@@ -1,4 +1,5 @@
 import { defineComponent, ComponentPublicInstance, h, inject } from 'vue'
+import type { App } from 'vue'
 import { config, mount } from '../src'
 import Hello from './components/Hello.vue'
 import ComponentWithSlots from './components/ComponentWithSlots.vue'
@@ -51,6 +52,43 @@ describe('config', () => {
     })
   })
 
+  describe('config integrity', () => {
+    it('should not leak config when plugins overwrite globalProperties', async () => {
+      // test with a function because it's not an "easy to clone" primitive type
+      const globalRouterMock = { push: jest.fn() }
+      const pluginRouterMock = { push: jest.fn() }
+      const Component = defineComponent({ template: '<div />' })
+
+      class Plugin {
+        static install(_app: App) {
+          _app.config.globalProperties.$router = pluginRouterMock
+        }
+      }
+
+      config.global.config.globalProperties = {
+        $router: globalRouterMock
+      }
+
+      // first with plugin to overwrite globalRouterMock with pluginRouterMock
+      const wrapper1 = mount(Component, {
+        global: {
+          plugins: [Plugin]
+        }
+      })
+
+      // then without plugin to check if the plugin overwrite is gone
+      const wrapper2 = mount(Component)
+
+      wrapper1.vm.$router.push('/route-1')
+      wrapper2.vm.$router.push('/route-2')
+
+      expect(pluginRouterMock.push).toHaveBeenCalledTimes(1)
+      expect(pluginRouterMock.push).toHaveBeenCalledWith('/route-1')
+      expect(globalRouterMock.push).toHaveBeenCalledTimes(1)
+      expect(globalRouterMock.push).toHaveBeenCalledWith('/route-2')
+    })
+  })
+
   describe('renderStubDefaultSlot', () => {
     it('should override shallow option when set to true', () => {
       const comp = mount(ComponentWithSlots, {