diff --git a/abx_plugins/plugins/istilldontcareaboutcookies/tests/test_istilldontcareaboutcookies.py b/abx_plugins/plugins/istilldontcareaboutcookies/tests/test_istilldontcareaboutcookies.py
index 7fbd287..42a61b0 100755
--- a/abx_plugins/plugins/istilldontcareaboutcookies/tests/test_istilldontcareaboutcookies.py
+++ b/abx_plugins/plugins/istilldontcareaboutcookies/tests/test_istilldontcareaboutcookies.py
@@ -413,7 +413,9 @@ def check_cookie_consent_visibility(
         {{ puppeteer, browserWSEndpoint: '{cdp_url}' }},
         async (browser) => {{
             const page = await browser.newPage();
-            await page.setUserAgent('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36');
+            const browserUa = await browser.userAgent();
+            const realisticUa = browserUa.replace('HeadlessChrome/', 'Chrome/').replace(' Headless', '');
+            await page.setUserAgent(realisticUa);
             await page.setViewport({{ width: 1440, height: 900 }});
 
             console.error('Navigating to {test_url}...');
diff --git a/abx_plugins/plugins/modalcloser/tests/test_modalcloser.py b/abx_plugins/plugins/modalcloser/tests/test_modalcloser.py
index acc53e5..31a40a1 100755
--- a/abx_plugins/plugins/modalcloser/tests/test_modalcloser.py
+++ b/abx_plugins/plugins/modalcloser/tests/test_modalcloser.py
@@ -562,8 +562,11 @@ def test_hides_cookie_consent_on_filmin():
     });
 
     const page = await browser.newPage();
-    // Set real user agent to bypass headless detection
-    await page.setUserAgent('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36');
+    // Set a non-headless UA derived from the actual browser to bypass headless detection
+    // without baking a Chrome version into source that will go stale on upgrade.
+    const browserUa = await browser.userAgent();
+    const realisticUa = browserUa.replace('HeadlessChrome/', 'Chrome/').replace(' Headless', '');
+    await page.setUserAgent(realisticUa);
     await page.setViewport({ width: 1440, height: 900 });
 
     console.error('Navigating to filmin.es...');
diff --git a/abx_plugins/plugins/ublock/tests/test_ublock.py b/abx_plugins/plugins/ublock/tests/test_ublock.py
index 2d866f5..9e86a8f 100755
--- a/abx_plugins/plugins/ublock/tests/test_ublock.py
+++ b/abx_plugins/plugins/ublock/tests/test_ublock.py
@@ -333,7 +333,9 @@ def check_ad_blocking(cdp_url: str, test_url: str, env: dict, script_dir: Path)
         {{ puppeteer, browserWSEndpoint: '{cdp_url}' }},
         async (browser) => {{
             const page = await browser.newPage();
-            await page.setUserAgent('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36');
+            const browserUa = await browser.userAgent();
+            const realisticUa = browserUa.replace('HeadlessChrome/', 'Chrome/').replace(' Headless', '');
+            await page.setUserAgent(realisticUa);
             await page.setViewport({{ width: 1440, height: 900 }});
 
             // Track network requests