diff --git a/test/hooks/exclude-blacklisted.test.js b/test/hooks/exclude-blacklisted.test.js
new file mode 100644
index 0000000..b6faeaa
--- /dev/null
+++ b/test/hooks/exclude-blacklisted.test.js
@@ -0,0 +1,66 @@
+const assert = require('assert');
+const feathers = require('@feathersjs/feathers');
+const excludeBlacklisted = require('../../server/hooks/exclude-blacklisted');
+
+let app;
+let usersettings = {};
+beforeEach(() => {
+  // Create a new plain Feathers application
+  app = feathers();
+
+  // Register a dummy custom service that just return the
+  // message data back
+  app.use('/usersettings', {
+    async find() {
+      return {
+        data: [usersettings]
+      };
+    }
+  });
+});
+
+describe('\'exclude-blacklisted\' hook', () => {
+  context('given a blacklist', () => {
+    let mock;
+    beforeEach(() => {
+      usersettings = { blacklist: ['4711'] };
+      mock = {
+        type: 'before',
+        method: 'find',
+        params: {
+          user: { _id: 'whatever' }
+        },
+        app
+      };
+    });
+
+    context('query param `userId` is an object', () => {
+      it('adds one key', () => {
+        mock.params.query = {
+          userId: { $ne: 'user id' }
+        };
+
+        const hook = excludeBlacklisted();
+        return hook(mock).then(result => {
+          assert.deepEqual(result.params.query.userId, {
+            $ne: 'user id',
+            $nin: ['4711']
+          });
+        });
+      });
+    });
+
+    context('query param `userId` is set to an exact id', () => {
+      it('has no effect', () => {
+        mock.params.query = {
+          userId: 'exact user id'
+        };
+
+        const hook = excludeBlacklisted();
+        return hook(mock).then(result => {
+          assert.deepEqual(result.params.query.userId, 'exact user id' );
+        });
+      });
+    });
+  });
+});