diff --git a/CHANGELOG.md b/CHANGELOG.md
index f1c232b..dcca2bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## Changelog
 
+#### 5.1.5 - 2025-11-11
+- Fixed fatal error due to new code to track AI referrer visit
+
 #### 5.1.4 - 2025-11-10
 - Fixed incorrectly forcing a new visit for visits referred by AI referrers
 
diff --git a/Columns/CampaignName.php b/Columns/CampaignName.php
index 0a3a766..7e00719 100644
--- a/Columns/CampaignName.php
+++ b/Columns/CampaignName.php
@@ -58,7 +58,7 @@ public function shouldForceNewVisit(Request $request, Visitor $visitor, Action $
         // That one will be detected as AI Assistant by core. But if someone reloads that page
         // and the utm source is still present, the check here might otherwise force a new visit,
         // if the `utm_source` parameter is configured.
-        if ((int)$visitor->getVisitorColumn('referer_type') === 8 && count($campaignDimensions) === 1) {
+        if ((int)$visitor->getVisitorColumn('referer_type') === 8 && !empty($campaignDimensions) && count($campaignDimensions) === 1) {
             $paramValue = reset($campaignDimensions);
             if (class_exists('Piwik\Plugins\Referrers\AIAssistant') && \Piwik\Plugins\Referrers\AIAssistant::getInstance()->getAIAssistantFromDomain($paramValue)) {
                 return false;
diff --git a/plugin.json b/plugin.json
index 3552a45..7c8b650 100644
--- a/plugin.json
+++ b/plugin.json
@@ -1,7 +1,7 @@
 {
     "name": "MarketingCampaignsReporting",
     "description": "Measure the effectiveness of your marketing campaigns. New reports, segments & track up to five channels: campaign, source, medium, keyword, content.",
-    "version": "5.1.4",
+    "version": "5.1.5",
     "keywords": ["Campaign", "Marketing", "Channels", "UTM tags"],
     "license": "GPL v3+",
     "homepage": "https://matomo.org",