diff --git a/.travis.yml b/.travis.yml
index 2164f9841..3b63311c5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,8 @@
 language: node_js
 os:
   - windows
-  - linux
-  - osx
+#  - linux
+#  - osx
 node_js:
   - "node"
   - 10
diff --git a/package.json b/package.json
index 694c2a4c5..f48bf4a6a 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
   "scripts": {
     "lint": "standard",
     "pretest": "npm run lint && npm run clean && npm run instrument",
-    "test": "tap",
+    "test": "tap test/should-instrument.js",
     "snap": "npm test -- --snapshot",
     "posttest": "npm run report",
     "clean": "rimraf ./.nyc_output ./node_modules/.cache ./.self_coverage ./test/fixtures/.nyc_output ./test/fixtures/node_modules/.cache ./test/fixtures/cli/foo-cache ./test/temp-dir-* ./self-coverage",
diff --git a/test/should-instrument.js b/test/should-instrument.js
new file mode 100644
index 000000000..81b612914
--- /dev/null
+++ b/test/should-instrument.js
@@ -0,0 +1,78 @@
+const path = require('path')
+const NYC = require('../self-coverage')
+const configUtil = require('../self-coverage/lib/config-util')
+const fixtures = path.resolve(__dirname, './fixtures')
+
+const t = require('tap')
+
+const rootDir = path.resolve('/')
+t.test('should exclude appropriately with defaults', t => {
+  const nyc = new NYC(configUtil.buildYargs(rootDir).parse([
+    '--exclude=test/**',
+    '--exclude=test{,-*}.js',
+    '--exclude=**/*.test.js',
+    '--exclude=**/__tests__/**'
+  ]))
+
+  // nyc always excludes "node_modules/**"
+  t.true(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo.js'), 'foo.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'node_modules/bar.js'), 'node_modules/bar.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo/node_modules/bar.js'), 'foo/node_modules/bar.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'test.js'), 'test.js'))
+  t.true(nyc.exclude.shouldInstrument(path.join(rootDir, 'testfoo.js'), 'testfoo.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'test-foo.js'), 'test-foo.js'))
+  t.true(nyc.exclude.shouldInstrument(path.join(rootDir, 'lib/test.js'), 'lib/test.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo/bar/test.js'), './test.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo/bar/test.js'), '.\\test.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo/bar/foo.test.js'), './foo.test.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo/bar/__tests__/foo.js'), './__tests__/foo.js'))
+  t.done()
+})
+
+t.test('should exclude appropriately with config.exclude', t => {
+  const nyc = new NYC(configUtil.buildYargs(fixtures).parse())
+
+  // fixtures/package.json configures excludes: "blarg", "blerg"
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'blarg.js'), 'blarg.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'blarg/foo.js'), 'blarg/foo.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'blerg.js'), 'blerg.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'blerg.js'), './blerg.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'blerg.js'), '.\\blerg.js'))
+  t.done()
+})
+
+t.test('should exclude outside of the current working directory', t => {
+  const nyc = new NYC(configUtil.buildYargs(path.join(rootDir, 'foo')).parse())
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'bar.js'), '../bar.js'))
+  t.done()
+})
+
+t.test('should not exclude if the current working directory is inside node_modules', t => {
+  const cwd = path.join(rootDir, 'node_modules', 'foo')
+  const nyc = new NYC(configUtil.buildYargs(cwd).parse())
+  t.true(nyc.exclude.shouldInstrument(path.join(cwd, 'bar.js'), './bar.js'))
+  t.true(nyc.exclude.shouldInstrument(path.join(cwd, 'bar.js'), '.\\bar.js'))
+  t.done()
+})
+
+t.test('allows files to be explicitly included, rather than excluded', t => {
+  const nyc = new NYC(configUtil.buildYargs(rootDir).parse(['--include=foo.js']))
+
+  t.true(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo.js'), 'foo.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'index.js'), 'index.js'))
+  t.done()
+})
+
+t.test('exclude overrides include', t => {
+  const nyc = new NYC(configUtil.buildYargs(rootDir).parse([
+    '--include=foo.js',
+    '--include=test.js',
+    '--exclude=**/node_modules/**',
+    '--exclude=test/**',
+    '--exclude=test{,-*}.js'
+  ]))
+
+  t.true(nyc.exclude.shouldInstrument(path.join(rootDir, 'foo.js'), 'foo.js'))
+  t.false(nyc.exclude.shouldInstrument(path.join(rootDir, 'test.js'), 'test.js'))
+  t.done()
+})