diff --git a/.gitignore b/.gitignore
index 1c3de6e..9ab4eac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,5 +3,6 @@ node_modules
 /client/*.js
 /client/*.map
 
-# don't ignore winchan.js
+# don't ignore winchan.js and modernizr-custom.js
 !/client/winchan.js
+!/client/modernizr-custom.js
diff --git a/client/modernizr-custom.js b/client/modernizr-custom.js
new file mode 100644
index 0000000..cea9367
--- /dev/null
+++ b/client/modernizr-custom.js
@@ -0,0 +1,3 @@
+/*! modernizr 3.3.1 (Custom Build) | MIT *
+ * https://modernizr.com/download/?-fetch-promises-setclasses !*/
+!function(e,n,s){function o(e,n){return typeof e===n}function i(){var e,n,s,i,a,f,l;for(var c in r)if(r.hasOwnProperty(c)){if(e=[],n=r[c],n.name&&(e.push(n.name.toLowerCase()),n.options&&n.options.aliases&&n.options.aliases.length))for(s=0;s<n.options.aliases.length;s++)e.push(n.options.aliases[s].toLowerCase());for(i=o(n.fn,"function")?n.fn():n.fn,a=0;a<e.length;a++)f=e[a],l=f.split("."),1===l.length?Modernizr[l[0]]=i:(!Modernizr[l[0]]||Modernizr[l[0]]instanceof Boolean||(Modernizr[l[0]]=new Boolean(Modernizr[l[0]])),Modernizr[l[0]][l[1]]=i),t.push((i?"":"no-")+l.join("-"))}}function a(e){var n=l.className,s=Modernizr._config.classPrefix||"";if(c&&(n=n.baseVal),Modernizr._config.enableJSClass){var o=new RegExp("(^|\\s)"+s+"no-js(\\s|$)");n=n.replace(o,"$1"+s+"js$2")}Modernizr._config.enableClasses&&(n+=" "+s+e.join(" "+s),c?l.className.baseVal=n:l.className=n)}var t=[],r=[],f={_version:"3.3.1",_config:{classPrefix:"",enableClasses:!0,enableJSClass:!0,usePrefixes:!0},_q:[],on:function(e,n){var s=this;setTimeout(function(){n(s[e])},0)},addTest:function(e,n,s){r.push({name:e,fn:n,options:s})},addAsyncTest:function(e){r.push({name:null,fn:e})}},Modernizr=function(){};Modernizr.prototype=f,Modernizr=new Modernizr,Modernizr.addTest("promises",function(){return"Promise"in e&&"resolve"in e.Promise&&"reject"in e.Promise&&"all"in e.Promise&&"race"in e.Promise&&function(){var n;return new e.Promise(function(e){n=e}),"function"==typeof n}()});var l=n.documentElement,c="svg"===l.nodeName.toLowerCase();Modernizr.addTest("fetch","fetch"in e),i(),a(t),delete f.addTest,delete f.addAsyncTest;for(var u=0;u<Modernizr._q.length;u++)Modernizr._q[u]();e.Modernizr=Modernizr}(window,document);
\ No newline at end of file