--- a/layout/tools/reftest/remotereftest.py
+++ b/layout/tools/reftest/remotereftest.py
@@ -225,16 +225,17 @@ class RemoteReftest(RefTest):
                                                server=options.remoteWebServer,
                                                port=options.httpPort)
         profileDir = profile.profile
 
         prefs = {}
         prefs["app.update.url.android"] = ""
         prefs["browser.firstrun.show.localepicker"] = False
         prefs["font.size.inflation.minTwips"] = 0
+        prefs["browser.zoom.globalZoom"] = 0
         prefs["reftest.remote"] = True
         prefs["datareporting.policy.dataSubmissionPolicyBypassAcceptance"] = True
 
         prefs["layout.css.devPixelsPerPx"] = "1.0"
         # Because Fennec is a little wacky (see bug 1156817) we need to load the
         # reftest pages at 1.0 zoom, rather than zooming to fit the CSS viewport.
         prefs["apz.allow_zooming"] = False