diff --git a/packages/test-exclude/index.js b/packages/test-exclude/index.js
index 2dc89144..2ec5480b 100644
--- a/packages/test-exclude/index.js
+++ b/packages/test-exclude/index.js
@@ -11,7 +11,8 @@ function TestExclude (opts) {
     relativePath: true,
     configKey: null, // the key to load config from in package.json.
     configPath: null, // optionally override requireMainFilename.
-    configFound: false
+    configFound: false,
+    excludeNodeModules: true
   }, opts)
 
   if (typeof this.include === 'string') this.include = [this.include]
@@ -31,7 +32,7 @@ function TestExclude (opts) {
     this.include = false
   }
 
-  if (this.exclude.indexOf('**/node_modules/**') === -1) {
+  if (this.excludeNodeModules && this.exclude.indexOf('**/node_modules/**') === -1) {
     this.exclude.push('**/node_modules/**')
   }
 
diff --git a/packages/test-exclude/test/test-exclude.js b/packages/test-exclude/test/test-exclude.js
index 9496edc7..ae0831c3 100644
--- a/packages/test-exclude/test/test-exclude.js
+++ b/packages/test-exclude/test/test-exclude.js
@@ -86,6 +86,21 @@ describe('testExclude', function () {
     e.shouldInstrument('src/foo.js').should.equal(true)
   })
 
+  it('allows node_modules default exclusion glob to be turned off, if excludeNodeModules === false', function () {
+    const e = exclude({
+      excludeNodeModules: false,
+      exclude: [
+        'node_modules/**',
+        '**/__test__/**'
+      ]
+    })
+    e.shouldInstrument('node_modules/cat.js').should.equal(false)
+    e.shouldInstrument('./banana/node_modules/cat.js').should.equal(true)
+    e.shouldInstrument('./banana/node_modules/__test__/cat.test.js').should.equal(false)
+    e.shouldInstrument('./banana/node_modules/__test__/cat-test.js').should.equal(false)
+    e.shouldInstrument('./banana/node_modules/__test__/cat.js').should.equal(false)
+  })
+
   it('allows negated exclude patterns', function () {
     const e = exclude({
       exclude: ['foo/**', '!foo/bar.js']