diff --git a/lib/runner.js b/lib/runner.js
index 23e9c3d..4009818 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -200,18 +200,34 @@ async function _executeTest(url, options) {
 async function getHistory(userUuid, userIp) {
   const db = require('../lib/db');
   
-  // If no identifiers provided, return empty or limit to anonymous? 
-  // For strict isolation, we require at least one.
+  // If no identifiers provided, return empty
   if (!userUuid && !userIp) return [];
 
   try {
-    const query = `
-      SELECT * FROM test_results 
-      WHERE user_uuid = $1 AND user_ip = $2 
-      ORDER BY timestamp DESC 
-      LIMIT 50
-    `;
-    const res = await db.pool.query(query, [userUuid, userIp]);
+    let query;
+    let params;
+
+    // Prioritize UUID if available and valid
+    if (userUuid && userUuid !== 'anonymous') {
+        query = `
+          SELECT * FROM test_results 
+          WHERE user_uuid = $1 
+          ORDER BY timestamp DESC 
+          LIMIT 50
+        `;
+        params = [userUuid];
+    } else {
+        // Fallback to IP if strictly anonymous
+        query = `
+          SELECT * FROM test_results 
+          WHERE user_ip = $1 
+          ORDER BY timestamp DESC 
+          LIMIT 50
+        `;
+        params = [userIp];
+    }
+
+    const res = await db.pool.query(query, params);
     
     // Convert DB rows back to simplified history objects
     return res.rows.map(row => ({