diff --git a/docs/migrations/migrate-from-v4.md b/docs/migrations/migrate-from-v4.md
index b00b73d4dd..7791cd02ec 100644
--- a/docs/migrations/migrate-from-v4.md
+++ b/docs/migrations/migrate-from-v4.md
@@ -124,6 +124,8 @@ Please consider switching to ESLint. You can check out [`tslint-to-eslint-config
 
 ### Unit-Jest Plugin
 
+* For Vue 2 projects, `vue-jest` is now required as a peer dependency, please install `vue-jest@^4.0.1` as a dev dependency to the project.
+* For TypeScript projects, `ts-jest` is now required as a peer dependency. Users need to install `ts-jest@26` manually to the project root.
 * The underlying `jest`-related packages are upgraded from v24 to v26. For most users the transition would be seamless. See their corresponding changelogs for more detail:
   * [jest, babel-jest](https://github.com/facebook/jest/blob/v26.6.3/CHANGELOG.md)
   * [ts-jest](https://github.com/kulshekhar/ts-jest/blob/v26.4.4/CHANGELOG.md)
diff --git a/packages/@vue/cli-plugin-unit-jest/generator/index.js b/packages/@vue/cli-plugin-unit-jest/generator/index.js
index 86508ba844..7ed8754f34 100644
--- a/packages/@vue/cli-plugin-unit-jest/generator/index.js
+++ b/packages/@vue/cli-plugin-unit-jest/generator/index.js
@@ -12,6 +12,7 @@ module.exports = (api, options, rootOptions, invoking) => {
       'test:unit': 'vue-cli-service test:unit'
     },
     devDependencies: {
+      'vue-jest': isVue3 ? '^5.0.0-0' : '^4.0.1',
       '@vue/test-utils': isVue3 ? '^2.0.0-0' : '^1.1.3'
     },
     jest: {
@@ -21,21 +22,6 @@ module.exports = (api, options, rootOptions, invoking) => {
     }
   })
 
-  if (isVue3) {
-    api.extendPackage({
-      devDependencies: {
-        'vue-jest': '^5.0.0-0',
-        // vue-jest 5.0.0-alpha.1 requires typescript to be present
-        'typescript': '~4.1.2'
-      },
-      jest: {
-        transform: {
-          '^.+\\.vue$': 'vue-jest'
-        }
-      }
-    })
-  }
-
   if (api.hasPlugin('eslint')) {
     applyESLint(api)
   }
@@ -71,7 +57,8 @@ const applyTS = (module.exports.applyTS = (api, invoking) => {
         : '@vue/cli-plugin-unit-jest/presets/typescript'
     },
     devDependencies: {
-      '@types/jest': '^26.0.20'
+      '@types/jest': '^26.0.20',
+      'ts-jest': '^26.5.3'
     }
   })
 
diff --git a/packages/@vue/cli-plugin-unit-jest/migrator/index.js b/packages/@vue/cli-plugin-unit-jest/migrator/index.js
new file mode 100644
index 0000000000..da6701968a
--- /dev/null
+++ b/packages/@vue/cli-plugin-unit-jest/migrator/index.js
@@ -0,0 +1,24 @@
+/** @param {import('@vue/cli/lib/MigratorAPI')} api MigratorAPI */
+module.exports = (api) => {
+  api.extendPackage(pkg => {
+    const toMerge = {}
+
+    const allDeps = {
+      ...pkg.dependencies,
+      ...pkg.devDependencies,
+      ...pkg.optionalDependencies
+    }
+
+    if (!allDeps['vue-jest']) {
+      // Likely a Vue 2 project, and uses the builtin preset.
+      // Because we used to add `vue-jest` v5 to dev deps for Vue 3 projects.
+      toMerge['vue-jest'] = '^4.0.1'
+    }
+
+    if (allDeps['@vue/cli-plugin-typescript'] && !allDeps['ts-jest']) {
+      toMerge['ts-jest'] = '^26.5.3'
+    }
+
+    return toMerge
+  })
+}
diff --git a/packages/@vue/cli-plugin-unit-jest/package.json b/packages/@vue/cli-plugin-unit-jest/package.json
index 80252adfe0..ffc368e459 100644
--- a/packages/@vue/cli-plugin-unit-jest/package.json
+++ b/packages/@vue/cli-plugin-unit-jest/package.json
@@ -32,14 +32,21 @@
     "jest": "^26.6.3",
     "jest-serializer-vue": "^2.0.2",
     "jest-transform-stub": "^2.0.0",
-    "jest-watch-typeahead": "^0.6.1",
-    "ts-jest": "^26.5.1",
-    "vue-jest": "^4.0.1"
+    "jest-watch-typeahead": "^0.6.1"
   },
   "devDependencies": {
-    "@vue/test-utils": "^1.1.3"
+    "@vue/test-utils": "^1.1.3",
+    "ts-jest": "^26.5.3",
+    "vue-jest": "^4.0.1"
   },
   "peerDependencies": {
-    "@vue/cli-service": "^3.0.0 || ^4.0.0 || ^5.0.0-0"
+    "@vue/cli-service": "^3.0.0 || ^4.0.0 || ^5.0.0-0",
+    "vue-jest": "^4.0.1 || ^5.0.0-0",
+    "ts-jest": "^26.5.3"
+  },
+  "peerDependenciesMeta": {
+    "ts-jest": {
+      "optional": true
+    }
   }
 }