diff --git a/browser/net/brave_site_hacks_network_delegate_helper.cc b/browser/net/brave_site_hacks_network_delegate_helper.cc
index d0281b4528d2..3058a5392f64 100644
--- a/browser/net/brave_site_hacks_network_delegate_helper.cc
+++ b/browser/net/brave_site_hacks_network_delegate_helper.cc
@@ -55,6 +55,8 @@ const std::string& GetQueryStringTrackers() {
            "wickedid",
            // https://github.com/brave/brave-browser/issues/11578
            "yclid",
+           // https://github.com/brave/brave-browser/issues/8975
+           "__s",
            // https://github.com/brave/brave-browser/issues/9019
            "_hsenc", "__hssc", "__hstc", "__hsfp", "hsCtaTracking"}),
       "|"));
diff --git a/browser/net/brave_site_hacks_network_delegate_helper_unittest.cc b/browser/net/brave_site_hacks_network_delegate_helper_unittest.cc
index 1824400f07ea..00bbe2f58d10 100644
--- a/browser/net/brave_site_hacks_network_delegate_helper_unittest.cc
+++ b/browser/net/brave_site_hacks_network_delegate_helper_unittest.cc
@@ -170,6 +170,7 @@ TEST(BraveSiteHacksNetworkDelegateHelperTest, QueryStringUntouched) {
       "https://example.com/?%20fbclid=1",
       "https://example.com/#fbclid=1",
       "https://example.com/1;k=v;&a=b&c=d&gclid=1234;%3fhttp://ad.co/?e=f&g=1",
+      "https://example.com/?__ss=1234-abcd",
   });
   for (const auto& url : urls) {
     auto brave_request_info =
@@ -251,6 +252,7 @@ TEST(BraveSiteHacksNetworkDelegateHelperTest, QueryStringFiltered) {
            "https://example.com/?fbclid=&foo=1&bar=2"},
           {"http://u:p@example.com/path/file.html?foo=1&fbclid=abcd#fragment",
            "http://u:p@example.com/path/file.html?foo=1#fragment"},
+          {"https://example.com/?__s=1234-abcd", "https://example.com/"},
           // Obscure edge cases that break most parsers:
           {"https://example.com/?fbclid&foo&&gclid=2&bar=&%20",
            "https://example.com/?fbclid&foo&&bar=&%20"},