diff --git a/src/General/Polyfill.coffee b/src/General/Polyfill.coffee
index df2f7c030..6bb91c3ad 100644
--- a/src/General/Polyfill.coffee
+++ b/src/General/Polyfill.coffee
@@ -1,9 +1,11 @@
 Polyfill =
   init: ->
     @toBlob()
+    $.global @toBlob
+    return
   toBlob: ->
     return if HTMLCanvasElement::toBlob
-    HTMLCanvasElement::toBlob = (cb, type='image/png', encoderOptions) ->
+    HTMLCanvasElement::toBlob = (cb, type='image/png', encoderOptions=null) ->
       url = @toDataURL type, encoderOptions
       data = atob url[url.indexOf(',')+1..]
       # DataUrl to Binary code from Aeosynth's 4chan X repo
@@ -12,4 +14,4 @@ Polyfill =
       for i in [0...l] by 1
         ui8a[i] = data.charCodeAt i
       cb new Blob [ui8a], {type}
-    $.globalEval "HTMLCanvasElement.prototype.toBlob = (#{HTMLCanvasElement::toBlob});"
+    return