diff --git a/README.md b/README.md
index 2a0d8c7..9034fee 100644
--- a/README.md
+++ b/README.md
@@ -116,6 +116,18 @@ const export = keystore.export_verification_data();
 keystore.import_verification_data(export);
 ```
 
+### Exporting and importing blacklist entries across server instances
+
+```js
+const {blacklist} = require('@sapphirecode/auth-server-helper');
+
+const export = blacklist.export_blacklist();
+
+// second instance
+
+blacklist.import_blacklist(export);
+```
+
 ## License
 
 MIT © Timo Hocker <timo@scode.ovh>
diff --git a/lib/Blacklist.ts b/lib/Blacklist.ts
index 6029b68..2d3d73b 100644
--- a/lib/Blacklist.ts
+++ b/lib/Blacklist.ts
@@ -43,6 +43,14 @@ class Blacklist {
 
     return true;
   }
+
+  public export_blacklist (): Signature[] {
+    return this._signatures;
+  }
+
+  public import_blacklist (data: Signature[]): void {
+    this._signatures.push (...data);
+  }
 }
 
 const bl = (new Blacklist);
diff --git a/test/spec/Blacklist.ts b/test/spec/Blacklist.ts
index bfa56d5..3edc32a 100644
--- a/test/spec/Blacklist.ts
+++ b/test/spec/Blacklist.ts
@@ -5,7 +5,7 @@
  * Created by Timo Hocker <timo@scode.ovh>, December 2020
  */
 
-import blacklist from '../../lib/Blacklist';
+import blacklist, { Blacklist } from '../../lib/Blacklist';
 import { clock_finalize, clock_setup } from '../Helper';
 
 // eslint-disable-next-line max-lines-per-function
@@ -60,4 +60,16 @@ describe ('blacklist', () => {
     expect (blacklist.is_valid ('baz'))
       .toBeFalse ();
   });
+
+  it ('should export and import data', () => {
+    const exp = blacklist.export_blacklist ();
+    // eslint-disable-next-line dot-notation
+    expect (blacklist['_signatures'])
+      .toEqual (exp);
+    const bl2 = (new Blacklist);
+    bl2.import_blacklist (exp);
+    // eslint-disable-next-line dot-notation
+    expect (bl2['_signatures'])
+      .toEqual (exp);
+  });
 });