diff --git a/src/General/Settings.coffee b/src/General/Settings.coffee
index d0347aff1..2dc4966c1 100755
--- a/src/General/Settings.coffee
+++ b/src/General/Settings.coffee
@@ -103,7 +103,7 @@ Settings =
         description = arr[1]
         div = $.el 'div',
           <%= html('<label><input type="checkbox" name="${key}">${key}</label><span class="description">: ${description}</span>') %>
-        div.hidden = true if chrome? and key is 'Remember QR Size' # XXX not supported
+        div.hidden = true if $.engine isnt 'gecko' and key is 'Remember QR Size' # XXX not supported
         input = $ 'input', div
         $.on input, 'change', ->
           @parentNode.parentNode.dataset.checked = @checked
diff --git a/src/Images/ImageCommon.coffee b/src/Images/ImageCommon.coffee
index 582428198..a5adc925a 100644
--- a/src/Images/ImageCommon.coffee
+++ b/src/Images/ImageCommon.coffee
@@ -83,7 +83,7 @@ ImageCommon =
       $.off video, 'mouseover', handler
       # Hacky workaround for Firefox forever-loading bug for very short videos
       t = new Date().getTime()
-      $.asap (-> chrome? or (video.readyState >= 3 and video.currentTime <= Math.max 0.1, (video.duration - 0.5)) or new Date().getTime() >= t + 1000), ->
+      $.asap (-> $.engine isnt 'gecko' or (video.readyState >= 3 and video.currentTime <= Math.max 0.1, (video.duration - 0.5)) or new Date().getTime() >= t + 1000), ->
         video.controls = true
     $.on video, 'mouseover', handler
 
diff --git a/src/Images/ImageLoader.coffee b/src/Images/ImageLoader.coffee
index eff4718fd..a6b9b0ee5 100755
--- a/src/Images/ImageLoader.coffee
+++ b/src/Images/ImageLoader.coffee
@@ -63,7 +63,7 @@ ImageLoader =
       clone.file.thumb.preload = 'auto' for clone in post.clones
       thumb.preload = 'auto'
       # XXX Cloned video elements with poster in Firefox cause momentary display of image loading icon.
-      if !chrome?
+      if $.engine is 'gecko'
         $.on thumb, 'loadeddata', -> @removeAttribute 'poster'
       return
 
diff --git a/src/Monitoring/Unread.coffee b/src/Monitoring/Unread.coffee
index e3c7a0c5f..3d8d820c8 100755
--- a/src/Monitoring/Unread.coffee
+++ b/src/Monitoring/Unread.coffee
@@ -243,6 +243,5 @@ Unread =
           Favicon[if isDead then 'unreadDead' else 'unread']
         else
           Favicon[if isDead then 'dead' else 'default']
-      unless chrome?
-        # `favicon.href = href` doesn't work on Firefox.
-        $.add d.head, Favicon.el
+      # `favicon.href = href` doesn't work on Firefox.
+      $.add d.head, Favicon.el
diff --git a/src/Posting/QR.coffee b/src/Posting/QR.coffee
index 974b18e07..0e831b525 100644
--- a/src/Posting/QR.coffee
+++ b/src/Posting/QR.coffee
@@ -202,7 +202,7 @@ QR =
           body: el.textContent
           icon: Favicon.logo
         notif.onclick = -> window.focus()
-        if chrome?
+        if $.engine isnt 'gecko'
           # Firefox automatically closes notifications
           # so we can't control the onclose properly.
           notif.onclose = -> notice.close()
@@ -530,7 +530,7 @@ QR =
     # We don't receive blur events from captcha iframe.
     $.on d, 'click', QR.focus
 
-    unless chrome?
+    if $.engine is 'gecko'
       nodes.pasteArea.hidden = false
       new MutationObserver(QR.pasteFF).observe nodes.pasteArea, {childList: true}
 
@@ -543,8 +543,8 @@ QR =
       event = if node.nodeName is 'SELECT' then 'change' else 'input'
       $.on nodes[name], event, save
 
-    # XXX Chromium treats width and height as min-width and min-height
-    if !chrome? and Conf['Remember QR Size']
+    # XXX Blink and WebKit treat width and height of <textarea>s as min-width and min-height
+    if $.engine is 'gecko' and Conf['Remember QR Size']
       $.get 'QR Size', '', (item) ->
         nodes.com.style.cssText = item['QR Size']
       $.on nodes.com, 'mouseup', (e) ->