diff --git a/README.md b/README.md
index 42d9b85..d6cbb05 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,8 @@ The following query string parameters are stripped:
   - `_hsmi`
 - Instagram
   - `igshid`
+- [Klaviyo](https://www.klaviyo.com/)
+  - `utm_klaviyo_id`
 - Mailchimp
   - `mc_cid`
   - `mc_eid`
diff --git a/background.js b/background.js
index d0ef5c2..2a8c340 100644
--- a/background.js
+++ b/background.js
@@ -11,7 +11,7 @@ const searchPattern = new RegExp('utm_|stm_|clid|_hs|icid|igshid|mc_|mkt_tok|ycl
  */
 const replacePattern = new RegExp(
     '([?&]' +
-    '(icid|mkt_tok|(g|fb)clid|igshid|_hs(enc|mi)|mc_[ce]id|(utm|stm)_(id|source|medium|term|campaign|content|cid|reader|referrer|name|social|social-type)|rb_clickid|yclid|_openstat|wickedid|otc|oly_(anon|enc)_id|soc_(src|trk)|cvid|oicd|bx_heid|openExternalBrowser|cm_mmc|luid|tum_medium|_branch_match_id|_branch_referrer)' +
+    '(icid|mkt_tok|(g|fb)clid|igshid|_hs(enc|mi)|mc_[ce]id|(utm|stm)_(id|source|medium|term|campaign|content|cid|reader|referrer|name|social|social-type|klaviyo_id)|rb_clickid|yclid|_openstat|wickedid|otc|oly_(anon|enc)_id|soc_(src|trk)|cvid|oicd|bx_heid|openExternalBrowser|cm_mmc|luid|tum_medium|_branch_match_id|_branch_referrer)' +
     '=[^&#]*)',
     'ig');