diff --git a/src/drivers/npm/driver.js b/src/drivers/npm/driver.js
index ae83bce7d..eb912513e 100644
--- a/src/drivers/npm/driver.js
+++ b/src/drivers/npm/driver.js
@@ -605,7 +605,7 @@ class Site {
       const cookies = (await page.cookies()).reduce(
         (cookies, { name, value }) => ({
           ...cookies,
-          [name]: [value],
+          [name.toLowerCase()]: [value],
         }),
         {}
       )
diff --git a/src/drivers/webextension/js/driver.js b/src/drivers/webextension/js/driver.js
index 358e1537e..eedc4463a 100644
--- a/src/drivers/webextension/js/driver.js
+++ b/src/drivers/webextension/js/driver.js
@@ -325,7 +325,7 @@ const Driver = {
       ).reduce(
         (cookies, { name, value }) => ({
           ...cookies,
-          [name]: [value],
+          [name.toLowerCase()]: [value],
         }),
         {}
       )