diff --git a/core/application.mjs b/core/application.mjs
index f3ddbe2..153ee34 100644
--- a/core/application.mjs
+++ b/core/application.mjs
@@ -379,7 +379,7 @@ export default class Application extends EventEmitter {
           rej(errTimeout)
         }, this.config.startWaitUntilFail)
 
-        let startRes = this.module.start(this.http, this.config.port, this.ctx)
+        let startRes = this.module.start(this.http, this.config.port || null, this.ctx)
         if (startRes && startRes.then) {
           return startRes.then(res, rej)
         }
diff --git a/core/lib.mjs b/core/lib.mjs
index f1a5094..1f85acb 100644
--- a/core/lib.mjs
+++ b/core/lib.mjs
@@ -1,6 +1,7 @@
 import Util from './util.mjs'
 import getLog from './log.mjs'
 import GetDB from './db.mjs'
+import Application from './application.mjs'
 import StaticProvider from './providers/static.mjs'
 import Core from './core.mjs'
 
@@ -11,7 +12,7 @@ export default class ServiceCore {
     }
     this._root_import_meta_url = root_import_meta_url
     this.util = new Util(this._root_import_meta_url)
-    this.dbfilename = dbname
+    this.dbfilename = dbfilename
     this.log = getLog(name)
     this.name = name
     this.config = {}
@@ -20,6 +21,10 @@ export default class ServiceCore {
     this.app = null
   }
 
+  setConfig(config) {
+    this.config[this.name] = config
+  }
+
   async init(module = null) {
     this.db = await GetDB(this.config, this.log, this.dbfilename)
     this.core = new Core(this.db, this.util, this.log)
diff --git a/index.mjs b/index.mjs
index 4643cc3..1ad1c94 100644
--- a/index.mjs
+++ b/index.mjs
@@ -1,6 +1,6 @@
 import bunyan from 'bunyan-lite'
 import { runner } from './core/runner.mjs'
-import { ServiceCore } from './core/lib.mjs'
+import ServiceCore from './core/lib.mjs'
 import Core from './core/core.mjs'
 import Application from './core/application.mjs'
 import Util from './core/util.mjs'
diff --git a/test/lib.test.mjs b/test/lib.test.mjs
new file mode 100644
index 0000000..752bb32
--- /dev/null
+++ b/test/lib.test.mjs
@@ -0,0 +1,64 @@
+import { Eltro as t, assert, stub } from 'eltro'
+import * as sc from '../index.mjs'
+
+t.describe('', function() {
+  const module = {
+    start: stub()
+  }
+
+  t.beforeEach(function() {
+    module.start.reset()
+  })
+
+  t.test('should have ServiceCore defined', function() {
+    assert.ok(sc.ServiceCore)
+  })
+
+  t.test('constructor should work', function() {
+    const assertAppName = 'Gondola'
+    let core = new sc.ServiceCore(assertAppName, import.meta.url)
+    assert.strictEqual(core.util._root_import_meta_url, import.meta.url)
+    assert.strictEqual(core.name, assertAppName)
+  })
+
+  t.test('should support proper init', async function() {
+    const assertAppName = 'Hero Combat'
+    let core = new sc.ServiceCore(assertAppName, import.meta.url)
+    await core.init(module)
+
+    assert.strictEqual(core.app.name, assertAppName)
+    assert.strictEqual(core.app.module, module)
+  })
+
+  t.test('should call module start', async function() {
+    const assertError = new Error('Inbo')
+    module.start.rejects(assertError)
+    
+    let core = new sc.ServiceCore('testapp', import.meta.url)
+    await core.init(module)
+    let err = await assert.isRejected(core.run())
+    assert.strictEqual(err, assertError)
+    assert.strictEqual(module.start.firstCall[0], core.app.http)
+    assert.strictEqual(module.start.firstCall[1], null)
+    assert.strictEqual(module.start.firstCall[2], core.app.ctx)
+  })
+
+  t.test('should support overwriting config', async function() {
+    const assertError = new Error('Inbo')
+    const assertPort = 9382
+    module.start.rejects(assertError)
+    
+    let core = new sc.ServiceCore('testapp', import.meta.url)
+
+    core.setConfig({
+      port: assertPort
+    })
+    await core.init(module)
+    
+    let err = await assert.isRejected(core.run())
+    assert.strictEqual(err, assertError)
+    assert.strictEqual(module.start.firstCall[0], core.app.http)
+    assert.strictEqual(module.start.firstCall[1], assertPort)
+    assert.strictEqual(module.start.firstCall[2], core.app.ctx)
+  })
+})