--- a/testing/mozharness/mozharness/mozilla/testing/testbase.py
+++ b/testing/mozharness/mozharness/mozilla/testing/testbase.py
@@ -194,17 +194,17 @@ class TestingMixin(VirtualenvMixin, Buil
         elif self.installer_url:
             symbols_url = self.query_prefixed_build_dir_url('.crashreporter-symbols.zip')
 
             # Check if the URL exists. If not, use none to allow mozcrash to auto-check for symbols
             try:
                 if symbols_url:
                     self._urlopen(symbols_url, timeout=120)
                     self.symbols_url = symbols_url
-            except (urllib2.URLError, socket.error, socket.timeout):
+            except (urllib2.HTTPError, urllib2.URLError, socket.error, socket.timeout):
                 self.exception("Can't figure out symbols_url from installer_url: %s!" % self.installer_url, level=WARNING)
 
         # If no symbols URL can be determined let minidump_stackwalk query the symbols.
         # As of now this only works for Nightly and release builds.
         if not self.symbols_url:
             self.warning("No symbols_url found. Let minidump_stackwalk query for symbols.")
 
         return self.symbols_url