diff --git a/packages/core/integration-tests/test/babel.js b/packages/core/integration-tests/test/babel.js
index cbd333f9cf3..5d49c04f334 100644
--- a/packages/core/integration-tests/test/babel.js
+++ b/packages/core/integration-tests/test/babel.js
@@ -1,5 +1,6 @@
 // @flow
 import assert from 'assert';
+import invariant from 'assert';
 import path from 'path';
 import {
   bundle,
@@ -415,6 +416,35 @@ describe('babel', function () {
       assert(distFile.includes('something different'));
     });
 
+    it('should rebuild when declared external dependencies change', async function () {
+      let inputDir = tempy.directory();
+      let filepath = path.join(inputDir, 'file.txt');
+
+      await fs.ncp(
+        path.join(__dirname, 'integration/babel-external-deps'),
+        inputDir,
+      );
+
+      let b = bundler(path.join(inputDir, 'index.js'), {
+        outputFS: fs,
+        shouldAutoInstall: true,
+      });
+
+      subscription = await b.watch();
+      let build = await getNextBuild(b);
+      invariant(build.type === 'buildSuccess');
+      let distFile = await fs.readFile(path.join(distDir, 'index.js'), 'utf8');
+      assert(distFile.includes('foo'));
+      assert(!distFile.includes('bar'));
+
+      await fs.writeFile(filepath, 'bar');
+      build = await getNextBuild(b);
+      invariant(build.type === 'buildSuccess');
+      distFile = await fs.readFile(path.join(distDir, 'index.js'), 'utf8');
+      assert(distFile.includes('bar'));
+      assert(!distFile.includes('foo'));
+    });
+
     it('should invalidate babel.config.js across runs', async function () {
       let dateRe = /return (\d+);/;
 
diff --git a/packages/core/integration-tests/test/integration/babel-external-deps/.babelrc b/packages/core/integration-tests/test/integration/babel-external-deps/.babelrc
new file mode 100644
index 00000000000..ce4a6735b9c
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/babel-external-deps/.babelrc
@@ -0,0 +1,3 @@
+{
+	"plugins": [["./plugin.js", { "filename": "file.txt" }]]
+}
diff --git a/packages/core/integration-tests/test/integration/babel-external-deps/file.txt b/packages/core/integration-tests/test/integration/babel-external-deps/file.txt
new file mode 100644
index 00000000000..257cc5642cb
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/babel-external-deps/file.txt
@@ -0,0 +1 @@
+foo
diff --git a/packages/core/integration-tests/test/integration/babel-external-deps/index.js b/packages/core/integration-tests/test/integration/babel-external-deps/index.js
new file mode 100644
index 00000000000..97ecfbae3a7
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/babel-external-deps/index.js
@@ -0,0 +1 @@
+console.log(REPLACE_ME);
diff --git a/packages/core/integration-tests/test/integration/babel-external-deps/package.json b/packages/core/integration-tests/test/integration/babel-external-deps/package.json
new file mode 100644
index 00000000000..dd236006194
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/babel-external-deps/package.json
@@ -0,0 +1,4 @@
+{
+  "name": "babel-external-deps",
+  "version": "1.0.0"
+}
diff --git a/packages/core/integration-tests/test/integration/babel-external-deps/plugin.js b/packages/core/integration-tests/test/integration/babel-external-deps/plugin.js
new file mode 100644
index 00000000000..814d985a55f
--- /dev/null
+++ b/packages/core/integration-tests/test/integration/babel-external-deps/plugin.js
@@ -0,0 +1,21 @@
+const fs = require("fs");
+const path = require("path");
+
+module.exports = function (api, { filename }) {
+  const { types: t } = api;
+
+  const filepath = path.join(__dirname, filename);
+  const contents = fs.readFileSync(filepath, "utf8");
+  api.cache.never();
+  api.addExternalDependency(filepath);
+
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name === "REPLACE_ME") {
+          path.replaceWith(t.stringLiteral(contents));
+        }
+      },
+    },
+  };
+};
diff --git a/packages/core/integration-tests/test/integration/babel-external-deps/yarn.lock b/packages/core/integration-tests/test/integration/babel-external-deps/yarn.lock
new file mode 100644
index 00000000000..e69de29bb2d