diff --git a/src/protections/MentionSpam.ts b/src/protections/MentionSpam.ts
index 10286c27..a14fa14e 100644
--- a/src/protections/MentionSpam.ts
+++ b/src/protections/MentionSpam.ts
@@ -104,6 +104,7 @@ export class MentionSpam extends Protection {
                 // Redact the event
                 if (!mjolnir.config.noop) {
                     await mjolnir.client.redactEvent(roomId, event['event_id'], "Message was detected as spam.");
+                    mjolnir.unlistedUserRedactionHandler.addUser(event['sender']);
                 } else {
                     await mjolnir.managementRoomOutput.logMessage(LogLevel.WARN, "MentionSpam", `Tried to redact ${event['event_id']} in ${roomId} but Mjolnir is running in no-op mode`, roomId);
                 }
diff --git a/test/integration/mentionSpamProtectionTest.ts b/test/integration/mentionSpamProtectionTest.ts
index 328508b1..3cb7e8db 100644
--- a/test/integration/mentionSpamProtectionTest.ts
+++ b/test/integration/mentionSpamProtectionTest.ts
@@ -107,5 +107,17 @@ describe("Test: Mention spam protection", function () {
 
         const fetchedDisplaynameEvent = await client.getEvent(room, messageWithDisplaynameMentions);
         assert.equal(Object.keys(fetchedDisplaynameEvent.content).length, 0, "This event should have been redacted");
+
+        // send messages after activating protection, they should be auto-redacted
+        const messages = [];
+        for (let i = 0; i < 10; i++) {
+            let nextMessage = await client.sendText(room, `hello${i}`);
+            messages.push(nextMessage)
+        }
+
+        messages.forEach(async (eventID) => {
+            await client.getEvent(room, eventID);
+            assert.equal(Object.keys(fetchedDisplaynameEvent.content).length, 0, "This event should have been redacted");
+        })
     });
 });
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