diff --git a/changelog.d/215.bugfix b/changelog.d/215.bugfix
new file mode 100644
index 00000000..c7a57354
--- /dev/null
+++ b/changelog.d/215.bugfix
@@ -0,0 +1 @@
+Fixed an issue where the bridge bot would change it's displayname if a webhook event is handled while `generic.userIdPrefix` is not set in the config.
diff --git a/src/Connections/GenericHook.ts b/src/Connections/GenericHook.ts
index c28c290e..0318dbf7 100644
--- a/src/Connections/GenericHook.ts
+++ b/src/Connections/GenericHook.ts
@@ -137,6 +137,10 @@ export class GenericHookConnection extends BaseConnection implements IConnection
             return;
         }
         const sender = this.getUserId();
+        if (sender === this.as.botUserId) {
+            // Don't set the global displayname for the bot.
+            return;   
+        }
         const intent = this.as.getIntentForUserId(sender);
         const expectedDisplayname = `${this.state.name} (Webhook)`;