--- a/testing/mozharness/mozharness/mozilla/testing/verify_tools.py
+++ b/testing/mozharness/mozharness/mozilla/testing/verify_tools.py
@@ -53,16 +53,21 @@ class VerifyToolsMixin(object):
             return []
 
         def get_automationrelevance():
             response = self.load_json_url(url)
             return response
 
         dirs = self.query_abs_dirs()
         mozinfo.find_and_update_from_json(dirs['abs_test_install_dir'])
+        if self.config.get('e10s') == True:
+            mozinfo.update({"e10s": True})
+            # Additional mozinfo properties like "headless" and "coverage" are
+            # also normally updated dynamically in the harness, but neither of
+            # these apply to the test-verify task.
 
         manifests = [
             (os.path.join(dirs['abs_mochitest_dir'], 'tests', 'mochitest.ini'), 'plain'),
             (os.path.join(dirs['abs_mochitest_dir'], 'chrome', 'chrome.ini'), 'chrome'),
             (os.path.join(dirs['abs_mochitest_dir'], 'browser', 'browser-chrome.ini'), 'browser-chrome'),
             (os.path.join(dirs['abs_mochitest_dir'], 'a11y', 'a11y.ini'), 'a11y'),
             (os.path.join(dirs['abs_xpcshell_dir'], 'tests', 'xpcshell.ini'), 'xpcshell'),
         ]