diff --git a/src/clients/firebase.js b/src/clients/firebase.js
index 6740cd2ba3..94c4882a60 100644
--- a/src/clients/firebase.js
+++ b/src/clients/firebase.js
@@ -262,7 +262,10 @@ export function setSessionUid() {
     Cookies.set(
       VALID_SESSION_UID_COOKIE,
       uid,
-      {expires: new Date(Date.now() + SESSION_TTL_MS)},
+      {
+        expires: new Date(Date.now() + SESSION_TTL_MS),
+        secure: true,
+      },
     );
   }
 }