diff --git a/lib/builder/webpack/client.config.js b/lib/builder/webpack/client.config.js
index eee26861ef..2d9d9de909 100644
--- a/lib/builder/webpack/client.config.js
+++ b/lib/builder/webpack/client.config.js
@@ -224,7 +224,7 @@ export default function webpackClientConfig () {
     const isDev = this.options.dev
     const extendedConfig = this.options.build.extend.call(this, config, {
       get dev () {
-        console.warn('dev has been deprecated into build.extend, please use isDev') // eslint-disable-line no-console
+        console.warn('dev has been deprecated in build.extend(), please use isDev') // eslint-disable-line no-console
         return isDev
       },
       isDev,
diff --git a/lib/builder/webpack/server.config.js b/lib/builder/webpack/server.config.js
index 6e2ebf6cfc..2ee1809780 100644
--- a/lib/builder/webpack/server.config.js
+++ b/lib/builder/webpack/server.config.js
@@ -79,7 +79,7 @@ export default function webpackServerConfig () {
     const isDev = this.options.dev
     const extendedConfig = this.options.build.extend.call(this, config, {
       get dev () {
-        console.warn('dev has been deprecated into build.extend, please use isDev') // eslint-disable-line no-console
+        console.warn('dev has been deprecated in build.extend(), please use isDev') // eslint-disable-line no-console
         return isDev
       },
       isDev,