diff --git a/.eslintrc.js b/.eslintrc.js
index 59afd2b1..946c5b28 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -174,7 +174,7 @@ module.exports = {
             "off",
             "always"
         ],
-        "guard-for-in": "off", //"error",
+        "guard-for-in": "error",
         "id-blacklist": "off",
         "id-match": "off",
         "import/order": "off",
diff --git a/src/excmds.ts b/src/excmds.ts
index 1b4567cb..2093514f 100644
--- a/src/excmds.ts
+++ b/src/excmds.ts
@@ -3625,7 +3625,8 @@ export async function sanitise(...args: string[]) {
          */
     }
     if (args.find(x => x === "all") !== undefined) {
-        for (const attr in dts) dts[attr] = true
+        for (const attr in dts)
+            if (Object.prototype.hasOwnProperty.call(dts, attr)) dts[attr] = true
     } else {
         // We bother checking if dts[x] is false because
         // browser.browsingData.remove() is very strict on the format of the