diff --git a/src/constants.ts b/src/constants.ts
index fdde793..2cbd75f 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -246,7 +246,8 @@ export function getLogConfig(overrides: Partial<LevelConfiguration> = {}): Level
   return {
     levelName: 'log',
     level: 6,
-    style: `font-size: 12px; border-radius: 4px; padding-right: 51px; background: linear-gradient(to right, #ecedef, #d9dce0); color: #333435; border-color: #bfc1c5;`,
+    style:
+      'font-size: 12px; border-radius: 4px; padding-right: 51px; background: linear-gradient(to right, #ecedef, #d9dce0); color: #333435; border-color: #bfc1c5;',
     terminalStyle: ['white', 'bgGray'],
     method: 'log',
     emoji: '🪵',
diff --git a/src/functions/seal.ts b/src/functions/seal.ts
index f5878e3..3c8ba52 100644
--- a/src/functions/seal.ts
+++ b/src/functions/seal.ts
@@ -21,11 +21,11 @@ export function SealedLog<N extends string, Msg, TBase extends Constructor = Con
 ) {
   const { formatters, middleware = [], ...cfgWithoutFormatters } = cfg.exportValues();
   const sealing: unknown = class Sealing extends Base {
-    _cfg = {
+    _cfg = new Configuration({
       ...structuredClone(cfgWithoutFormatters),
       formatters: { ...formatters },
       middleware: [...middleware],
-    };
+    });
     _modifierData = structuredClone(mods);
     modifierQueue = [...modifierQueue];
   };
diff --git a/test/seal.test.ts b/test/seal.test.ts
new file mode 100644
index 0000000..7b5c22c
--- /dev/null
+++ b/test/seal.test.ts
@@ -0,0 +1,31 @@
+import { afterEach, describe, expect, test, vi } from 'vitest';
+import adze, { setup, teardown } from '../src';
+
+/**
+ * @vitest-environment happy-dom
+ */
+
+describe('Configuration', () => {
+  afterEach(() => {
+    delete globalThis.$ADZE_ENV;
+    window.location.search = '';
+    teardown();
+  });
+
+  test('can seal an already sealed logger', () => {
+    console.log = vi.fn();
+
+    const logger1 = adze.withEmoji.seal();
+    const logger2 = logger1.ns('sealed').seal();
+
+    logger2.log('This is a log from a twice sealed logger.');
+
+    expect(console.log).toHaveBeenCalledWith(
+      '%c🪵 %c Log',
+      'font-size: 12px;',
+      'font-size: 12px; border-radius: 4px; padding-right: 51px; background: linear-gradient(to right, #ecedef, #d9dce0); color: #333435; border-color: #bfc1c5;',
+      '#sealed ',
+      'This is a log from a twice sealed logger.'
+    );
+  });
+});