diff --git a/.eslintrc.js b/.eslintrc.js
index 091dabb3c6cc..f2aab9610478 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -87,7 +87,6 @@ module.exports = {
   }, {
     // TODO: Bug 1246594. Empty this list once the rule has landed for all dirs
     "files": [
-      "parser/htmlparser/tests/mochitest/parser_datreader.js",
       "testing/marionette/event.js",
       "testing/mochitest/**",
       "testing/modules/tests/xpcshell/test_assert.js",
diff --git a/parser/htmlparser/tests/mochitest/parser_datreader.js b/parser/htmlparser/tests/mochitest/parser_datreader.js
index 5f610fcc80c3..97298208f913 100644
--- a/parser/htmlparser/tests/mochitest/parser_datreader.js
+++ b/parser/htmlparser/tests/mochitest/parser_datreader.js
@@ -43,7 +43,7 @@ function parseTestcase(testcase) {
     if (line == "#data")
       break;
     log(lines);
-    throw "Unknown test format.";
+    throw new Error("Unknown test format.");
   }
 
   var input = [];