--- a/browser/base/content/test/general/browser_parsable_css.js
+++ b/browser/base/content/test/general/browser_parsable_css.js
@@ -18,17 +18,17 @@ const kWhitelist = [
   // Tracked in bug 1004428.
   {sourceName: /aboutaccounts\/(main|normalize)\.css$/i},
   // TokBox SDK assets, see bug 1032469.
   {sourceName: /loop\/.*sdk-content\/.*\.css$/i},
   // Loop standalone client CSS uses placeholder cross browser pseudo-element
   {sourceName: /loop\/.*\.css$/i,
    errorMessage: /Unknown pseudo-class.*placeholder/i},
   {sourceName: /loop\/.*shared\/css\/common.css$/i,
-   errorMessage: /Unknown property 'user-select'/i},
+   errorMessage: /Unknown property .user-select./i},
   // Highlighter CSS uses a UA-only pseudo-class, see bug 985597.
   {sourceName: /highlighters\.css$/i,
    errorMessage: /Unknown pseudo-class.*moz-native-anonymous/i},
   // Responsive Design Mode CSS uses a UA-only pseudo-class, see Bug 1241714.
   {sourceName: /responsive-ua\.css$/i,
    errorMessage: /Unknown pseudo-class.*moz-dropdown-list/i},
 ];
 

--- a/browser/base/content/test/general/parsingTestHelpers.jsm
+++ b/browser/base/content/test/general/parsingTestHelpers.jsm
@@ -65,17 +65,18 @@ function iterateOverPath(path, extension
       let file = parentDir.clone();
       file.append(entry.name);
       // the build system might leave dead symlinks hanging around, which are
       // returned as part of the directory iterator, but don't actually exist:
       if (file.exists()) {
         let uriSpec = getURLForFile(file);
         files.push(Services.io.newURI(uriSpec, null, null));
       }
-    } else if (entry.name.endsWith(".ja") || entry.name.endsWith(".jar")) {
+    } else if (entry.name.endsWith(".ja") || entry.name.endsWith(".jar") ||
+               entry.name.endsWith(".zip") || entry.name.endsWith(".xpi")) {
       let file = parentDir.clone();
       file.append(entry.name);
       for (let extension of extensions) {
         let jarEntryIterator = generateEntriesFromJarFile(file, extension);
         files.push(...jarEntryIterator);
       }
     }
   };