diff --git a/tasks/lib/packages/__tests__/fixtures/fixture1/index.js b/tasks/lib/packages/__tests__/fixtures/fixture1/index.js
new file mode 100644
index 0000000000000..24b00f58ebd36
--- /dev/null
+++ b/tasks/lib/packages/__tests__/fixtures/fixture1/index.js
@@ -0,0 +1 @@
+console.log('I am fixture 1');
diff --git a/tasks/lib/packages/__tests__/fixtures/fixture1/node_modules/dep1/index.js b/tasks/lib/packages/__tests__/fixtures/fixture1/node_modules/dep1/index.js
new file mode 100644
index 0000000000000..17aefb3c74b91
--- /dev/null
+++ b/tasks/lib/packages/__tests__/fixtures/fixture1/node_modules/dep1/index.js
@@ -0,0 +1 @@
+console.log('I am dep 1');
diff --git a/tasks/lib/packages/__tests__/fixtures/fixture1/node_modules/dep1/package.json b/tasks/lib/packages/__tests__/fixtures/fixture1/node_modules/dep1/package.json
new file mode 100644
index 0000000000000..a2ccb021abcb9
--- /dev/null
+++ b/tasks/lib/packages/__tests__/fixtures/fixture1/node_modules/dep1/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "dep1",
+  "version": "0.0.2",
+  "license": "Apache-2.0"
+}
diff --git a/tasks/lib/packages/__tests__/fixtures/fixture1/package.json b/tasks/lib/packages/__tests__/fixtures/fixture1/package.json
new file mode 100644
index 0000000000000..d2d533591bcfd
--- /dev/null
+++ b/tasks/lib/packages/__tests__/fixtures/fixture1/package.json
@@ -0,0 +1,8 @@
+{
+  "name": "fixture1",
+  "version": "0.0.1",
+  "license": "MIT",
+  "dependencies": {
+    "dep1": "0.0.2"
+  }
+}
diff --git a/tasks/lib/packages/__tests__/installed_packages.js b/tasks/lib/packages/__tests__/installed_packages.js
new file mode 100644
index 0000000000000..4c47412a2a1f2
--- /dev/null
+++ b/tasks/lib/packages/__tests__/installed_packages.js
@@ -0,0 +1,59 @@
+import { resolve } from 'path';
+
+import { uniq } from 'lodash';
+import expect from 'expect.js';
+
+import { getInstalledPackages } from '../installed_packages';
+
+const KIBANA_ROOT = resolve(__dirname, '../../../../');
+const FIXTURE1_ROOT = resolve(__dirname, 'fixtures/fixture1');
+
+describe('tasks/lib/packages', () => {
+  describe('getInstalledPackages()', function () {
+
+    let kibanaPackages;
+    let fixture1Packages;
+    before(async function () {
+      this.timeout(30 * 1000);
+      [kibanaPackages, fixture1Packages] = await Promise.all([
+        getInstalledPackages({
+          directory: KIBANA_ROOT
+        }),
+        getInstalledPackages({
+          directory: FIXTURE1_ROOT
+        }),
+      ]);
+    });
+
+    it('requires a directory', async () => {
+      try {
+        await getInstalledPackages({});
+        throw new Error('expected getInstalledPackages() to reject');
+      } catch (err) {
+        expect(err.message).to.contain('directory');
+      }
+    });
+
+    it('reads all installed packages of a module', () => {
+      expect(fixture1Packages).to.eql([
+        {
+          name: 'dep1',
+          version: '0.0.2',
+          licenses: [ 'Apache-2.0' ],
+          directory: resolve(FIXTURE1_ROOT, 'node_modules/dep1'),
+          relative: 'node_modules/dep1',
+        }
+      ]);
+    });
+
+    it('returns a single entry for every package/version combo', () => {
+      const tags = kibanaPackages.map(pkg => `${pkg.name}@${pkg.version}`);
+      expect(tags).to.eql(uniq(tags));
+    });
+
+    it('does not include root package in the list', async () => {
+      expect(kibanaPackages.find(pkg => pkg.name === 'kibana')).to.be(undefined);
+      expect(fixture1Packages.find(pkg => pkg.name === 'fixture1')).to.be(undefined);
+    });
+  });
+});
diff --git a/tasks/lib/packages/installed_packages.js b/tasks/lib/packages/installed_packages.js
index 6a479317eb5d7..e34feb7478c4c 100644
--- a/tasks/lib/packages/installed_packages.js
+++ b/tasks/lib/packages/installed_packages.js
@@ -50,5 +50,6 @@ export async function getInstalledPackages(options = {}) {
         directory: realPath,
         relative: relative(directory, realPath)
       };
-    });
+    })
+    .filter(pkg => pkg.directory !== directory);
 }