diff --git a/FormData.js b/FormData.js
index 32bd5fc..68c80fe 100644
--- a/FormData.js
+++ b/FormData.js
@@ -101,6 +101,8 @@ if (typeof Blob !== 'undefined' && (typeof FormData === 'undefined' || !FormData
     }
   }
 
+  const escape = str => str.replace(/\n/g, '%0A').replace(/\r/g, '%0D').replace(/"/g, '%22')
+
   /**
    * @implements {Iterable}
    */
@@ -327,31 +329,17 @@ if (typeof Blob !== 'undefined' && (typeof FormData === 'undefined' || !FormData
      * @return {Blob} [description]
      */
     ['_blob'] () {
-      const boundary = '----formdata-polyfill-' + Math.random()
-      const chunks = []
-
-      for (const [name, value] of this) {
-        chunks.push(`--${boundary}\r\n`)
-
-        if (value instanceof Blob) {
-          chunks.push(
-            `Content-Disposition: form-data; name="${name}"; filename="${value.name}"\r\n` +
-            `Content-Type: ${value.type || 'application/octet-stream'}\r\n\r\n`,
-            value,
-            '\r\n'
-          )
-        } else {
-          chunks.push(
-            `Content-Disposition: form-data; name="${name}"\r\n\r\n${value}\r\n`
-          )
-        }
-      }
-
-      chunks.push(`--${boundary}--`)
+        const boundary = '----formdata-polyfill-' + Math.random(),
+          chunks = [],
+          p = `--${boundary}\r\nContent-Disposition: form-data; name="`
+        this.forEach((value, name) => typeof value == 'string'
+          ? chunks.push(p + escape(name) + `"\r\n\r\n${value}\r\n`)
+          : chunks.push(p + escape(name) + `"; filename="${escape(value.name)}"\r\nContent-Type: ${value.type||"application/octet-stream"}\r\n\r\n`, value, `\r\n`))
+        chunks.push(`--${boundary}--`)
+        return new Blob(chunks, {
+          type: "multipart/form-data; boundary=" + boundary
+        })
 
-      return new Blob(chunks, {
-        type: 'multipart/form-data; boundary=' + boundary
-      })
     }
 
     /**
diff --git a/esm.min.js b/esm.min.js
index c040f38..a86e6fa 100644
--- a/esm.min.js
+++ b/esm.min.js
@@ -1,9 +1,10 @@
-import B from 'fetch-blob'
+import C from 'fetch-blob'
 import F from 'fetch-blob/file.js'
 
 var {toStringTag:t,iterator:i,hasInstance:h}=Symbol,
 m='append,set,get,getAll,delete,keys,values,entries,forEach,constructor'.split(','),
-f=(a,b,c)=>(a+='',/^(Blob|File)$/.test(b?.[t])?[(c=c!==void 0?c+'':b[t]=='File'?b.name:'blob',a),b.name!==c||b[t]=='blob'?new F([b],c):b]:[a,b+''])
+f=(a,b,c)=>(a+='',/^(Blob|File)$/.test(b?.[t])?[(c=c!==void 0?c+'':b[t]=='File'?b.name:'blob',a),b.name!==c||b[t]=='blob'?new F([b],c):b]:[a,b+'']),
+e=c=>c.replace(/\n/g,'%0A').replace(/\r/g,'%0D').replace(/"/g,'%22')
 
 export const File = F
 
@@ -20,15 +21,12 @@ forEach(a,b){for(var [c,d]of this)a.call(b,d,c,this)}
 set(...a){var b=[],c=!0;a=f(...a);this.#d.forEach(d=>{d[0]===a[0]?c&&(c=!b.push(a)):b.push(d)});c&&b.push(a);this.#d=b}
 *entries(){yield*this.#d}
 *keys(){for(var[a]of this)yield a}
-*values(){for(var[,a]of this)yield a}
-}
+*values(){for(var[,a]of this)yield a}}
 
-export function formDataToBlob(formData){
-var b='----formdata-'+Math.random(),c=[],d=`--${b}\r\nContent-Disposition: form-data; name="`
-
-formData.forEach((v,n)=>typeof v==='string'
-?c.push(`${d}${n}"\r\n\r\n${v}\r\n--${b}--`)
-:c.push(`${d}${n}"; filename="${v.name}"\r\nContent-Type: ${v.type || 'application/octet-stream'}\r\n\r\n`,v,`\r\n--${b}--`))
-
-return new B(c,{type:'multipart/form-data; boundary='+b})
-}
+export function formDataToBlob (F,B=C){
+var b='----formdata-'+Math.random(),c=[],p=`--${b}\r\nContent-Disposition: form-data; name="`
+F.forEach((v,n)=>typeof v=='string'
+?c.push(p+e(n)+`"\r\n\r\n${v}\r\n`)
+:c.push(p+e(n)+`"; filename="${e(v.name)}"\r\nContent-Type: ${v.type||"application/octet-stream"}\r\n\r\n`, v, '\r\n'))
+c.push(`--${b}--`)
+return new B(c,{type:"multipart/form-data; boundary="+b})}
diff --git a/formdata-to-blob.js b/formdata-to-blob.js
index db5b74c..cae087b 100644
--- a/formdata-to-blob.js
+++ b/formdata-to-blob.js
@@ -1,3 +1,5 @@
+const escape = str => str.replace(/\n/g, '%0A').replace(/\r/g, '%0D').replace(/"/g, '%22')
+
 /**
  * pure function to convert any formData instance to a Blob
  * instances syncronus without reading all of the files
@@ -6,22 +8,25 @@
  * @param {Blob|*} [BlobClass=Blob] the Blob class to use when constructing it
  */
 export function formDataToBlob (formData, BlobClass = Blob) {
-  const boundary = '----formdata-' + Math.random()
+  const boundary = ('----formdata-polyfill-' + Math.random())
   const chunks = []
+  const prefix = `--${boundary}\r\nContent-Disposition: form-data; name="`
 
-  for (const [name, value] of formData) {
-    chunks.push(`--${boundary}\r\nContent-Disposition: form-data; name="${name}"`)
-
-    typeof value === 'string'
-      ? chunks.push(`\r\n\r\n${value}\r\n--${boundary}--`)
-      : chunks.push(
-        `; filename="${value.name}"\r\n` +
+  for (let [name, value] of formData) {
+    if (typeof value === 'string') {
+      chunks.push(prefix + escape(name) + `"\r\n\r\n${value}\r\n`)
+    } else {
+      chunks.push(
+        prefix + escape(name) + `"; filename="${escape(value.name)}"\r\n` +
         `Content-Type: ${value.type || 'application/octet-stream'}\r\n\r\n`,
         value,
-        `\r\n--${boundary}--`
+        '\r\n'
       )
+    }
   }
 
+  chunks.push(`--${boundary}--`)
+
   return new BlobClass(chunks, {
     type: 'multipart/form-data; boundary=' + boundary
   })
diff --git a/formdata.min.js b/formdata.min.js
index e30958f..890829c 100644
--- a/formdata.min.js
+++ b/formdata.min.js
@@ -1,7 +1,7 @@
 ;(function(){var h;function l(a){var c=0;return function(){return c<a.length?{done:!1,value:a[c++]}:{done:!0}}}var m="function"==typeof Object.defineProperties?Object.defineProperty:function(a,c,b){if(a==Array.prototype||a==Object.prototype)return a;a[c]=b.value;return a};
-function n(a){a=["object"==typeof globalThis&&globalThis,a,"object"==typeof window&&window,"object"==typeof self&&self,"object"==typeof global&&global];for(var c=0;c<a.length;++c){var b=a[c];if(b&&b.Math==Math)return b}throw Error("Cannot find global object");}var p=n(this);function r(a,c){if(c)a:{for(var b=p,d=a.split("."),e=0;e<d.length-1;e++){var f=d[e];if(!(f in b))break a;b=b[f]}d=d[d.length-1];e=b[d];f=c(e);f!=e&&null!=f&&m(b,d,{configurable:!0,writable:!0,value:f})}}
+function n(a){a=["object"==typeof globalThis&&globalThis,a,"object"==typeof window&&window,"object"==typeof self&&self,"object"==typeof global&&global];for(var c=0;c<a.length;++c){var b=a[c];if(b&&b.Math==Math)return b}throw Error("Cannot find global object");}var q=n(this);function r(a,c){if(c)a:{for(var b=q,d=a.split("."),e=0;e<d.length-1;e++){var f=d[e];if(!(f in b))break a;b=b[f]}d=d[d.length-1];e=b[d];f=c(e);f!=e&&null!=f&&m(b,d,{configurable:!0,writable:!0,value:f})}}
 r("Symbol",function(a){function c(f){if(this instanceof c)throw new TypeError("Symbol is not a constructor");return new b(d+(f||"")+"_"+e++,f)}function b(f,g){this.A=f;m(this,"description",{configurable:!0,writable:!0,value:g})}if(a)return a;b.prototype.toString=function(){return this.A};var d="jscomp_symbol_"+(1E9*Math.random()>>>0)+"_",e=0;return c});
-r("Symbol.iterator",function(a){if(a)return a;a=Symbol("Symbol.iterator");for(var c="Array Int8Array Uint8Array Uint8ClampedArray Int16Array Uint16Array Int32Array Uint32Array Float32Array Float64Array".split(" "),b=0;b<c.length;b++){var d=p[c[b]];"function"===typeof d&&"function"!=typeof d.prototype[a]&&m(d.prototype,a,{configurable:!0,writable:!0,value:function(){return u(l(this))}})}return a});function u(a){a={next:a};a[Symbol.iterator]=function(){return this};return a}
+r("Symbol.iterator",function(a){if(a)return a;a=Symbol("Symbol.iterator");for(var c="Array Int8Array Uint8Array Uint8ClampedArray Int16Array Uint16Array Int32Array Uint32Array Float32Array Float64Array".split(" "),b=0;b<c.length;b++){var d=q[c[b]];"function"===typeof d&&"function"!=typeof d.prototype[a]&&m(d.prototype,a,{configurable:!0,writable:!0,value:function(){return u(l(this))}})}return a});function u(a){a={next:a};a[Symbol.iterator]=function(){return this};return a}
 function v(a){var c="undefined"!=typeof Symbol&&Symbol.iterator&&a[Symbol.iterator];return c?c.call(a):{next:l(a)}}var w;if("function"==typeof Object.setPrototypeOf)w=Object.setPrototypeOf;else{var y;a:{var z={a:!0},A={};try{A.__proto__=z;y=A.a;break a}catch(a){}y=!1}w=y?function(a,c){a.__proto__=c;if(a.__proto__!==c)throw new TypeError(a+" is not extensible");return a}:null}var B=w;function C(){this.m=!1;this.j=null;this.v=void 0;this.h=1;this.u=this.C=0;this.l=null}
 function D(a){if(a.m)throw new TypeError("Generator is already running");a.m=!0}C.prototype.o=function(a){this.v=a};C.prototype.s=function(a){this.l={D:a,F:!0};this.h=this.C||this.u};C.prototype["return"]=function(a){this.l={"return":a};this.h=this.u};function E(a,c){a.h=3;return{value:c}}function F(a){this.g=new C;this.G=a}F.prototype.o=function(a){D(this.g);if(this.g.j)return G(this,this.g.j.next,a,this.g.o);this.g.o(a);return H(this)};
 function I(a,c){D(a.g);var b=a.g.j;if(b)return G(a,"return"in b?b["return"]:function(d){return{value:d,done:!0}},c,a.g["return"]);a.g["return"](c);return H(a)}F.prototype.s=function(a){D(this.g);if(this.g.j)return G(this,this.g.j["throw"],a,this.g.o);this.g.s(a);return H(this)};
@@ -9,12 +9,12 @@ function G(a,c,b,d){try{var e=c.call(a.g.j,b);if(!(e instanceof Object))throw ne
 function J(a){this.next=function(c){return a.o(c)};this["throw"]=function(c){return a.s(c)};this["return"]=function(c){return I(a,c)};this[Symbol.iterator]=function(){return this}}function K(a,c){var b=new J(new F(c));B&&a.prototype&&B(b,a.prototype);return b}
 if("undefined"!==typeof Blob&&("undefined"===typeof FormData||!FormData.prototype.keys)){var L=function(a,c){for(var b=0;b<a.length;b++)c(a[b])},M=function(a,c,b){if(c instanceof Blob){b=void 0!==b?String(b+""):"string"===typeof c.name?c.name:"blob";if(c.name!==b||"[object Blob]"===Object.prototype.toString.call(c))c=new File([c],b);return[String(a),c]}return[String(a),String(c)]},N=function(a,c){if(a.length<c)throw new TypeError(c+" argument required, but only "+a.length+" present.");},O="object"===
 typeof globalThis?globalThis:"object"===typeof window?window:"object"===typeof self?self:this,P=O.FormData,Q=O.XMLHttpRequest&&O.XMLHttpRequest.prototype.send,R=O.Request&&O.fetch,S=O.navigator&&O.navigator.sendBeacon,T=O.Element&&O.Element.prototype,U=O.Symbol&&Symbol.toStringTag;U&&(Blob.prototype[U]||(Blob.prototype[U]="Blob"),"File"in O&&!File.prototype[U]&&(File.prototype[U]="File"));try{new File([],"")}catch(a){O.File=function(c,b,d){c=new Blob(c,d||{});Object.defineProperties(c,{name:{value:b},
-lastModified:{value:+(d&&void 0!==d.lastModified?new Date(d.lastModified):new Date)},toString:{value:function(){return"[object File]"}}});U&&Object.defineProperty(c,U,{value:"File"});return c}}var V=function(a){this.i=[];var c=this;a&&L(a.elements,function(b){if(b.name&&!b.disabled&&"submit"!==b.type&&"button"!==b.type&&!b.matches("form fieldset[disabled] *"))if("file"===b.type){var d=b.files&&b.files.length?b.files:[new File([],"",{type:"application/octet-stream"})];L(d,function(e){c.append(b.name,
-e)})}else"select-multiple"===b.type||"select-one"===b.type?L(b.options,function(e){!e.disabled&&e.selected&&c.append(b.name,e.value)}):"checkbox"===b.type||"radio"===b.type?b.checked&&c.append(b.name,b.value):(d="textarea"===b.type?b.value.replace(/\r\n/g,"\n").replace(/\n/g,"\r\n"):b.value,c.append(b.name,d))})};h=V.prototype;h.append=function(a,c,b){N(arguments,2);this.i.push(M(a,c,b))};h["delete"]=function(a){N(arguments,1);var c=[];a=String(a);L(this.i,function(b){b[0]!==a&&c.push(b)});this.i=
-c};h.entries=function c(){var b,d=this;return K(c,function(e){1==e.h&&(b=0);if(3!=e.h)return b<d.i.length?e=E(e,d.i[b]):(e.h=0,e=void 0),e;b++;e.h=2})};h.forEach=function(c,b){N(arguments,1);for(var d=v(this),e=d.next();!e.done;e=d.next()){var f=v(e.value);e=f.next().value;f=f.next().value;c.call(b,f,e,this)}};h.get=function(c){N(arguments,1);var b=this.i;c=String(c);for(var d=0;d<b.length;d++)if(b[d][0]===c)return b[d][1];return null};h.getAll=function(c){N(arguments,1);var b=[];c=String(c);L(this.i,
-function(d){d[0]===c&&b.push(d[1])});return b};h.has=function(c){N(arguments,1);c=String(c);for(var b=0;b<this.i.length;b++)if(this.i[b][0]===c)return!0;return!1};h.keys=function b(){var d=this,e,f,g,k,q;return K(b,function(t){1==t.h&&(e=v(d),f=e.next());if(3!=t.h){if(f.done){t.h=0;return}g=f.value;k=v(g);q=k.next().value;return E(t,q)}f=e.next();t.h=2})};h.set=function(b,d,e){N(arguments,2);b=String(b);var f=[],g=M(b,d,e),k=!0;L(this.i,function(q){q[0]===b?k&&(k=!f.push(g)):f.push(q)});k&&f.push(g);
-this.i=f};h.values=function d(){var e=this,f,g,k,q,t;return K(d,function(x){1==x.h&&(f=v(e),g=f.next());if(3!=x.h){if(g.done){x.h=0;return}k=g.value;q=v(k);q.next();t=q.next().value;return E(x,t)}g=f.next();x.h=2})};V.prototype._asNative=function(){for(var d=new P,e=v(this),f=e.next();!f.done;f=e.next()){var g=v(f.value);f=g.next().value;g=g.next().value;d.append(f,g)}return d};V.prototype._blob=function(){for(var d="----formdata-polyfill-"+Math.random(),e=[],f=v(this),g=f.next();!g.done;g=f.next()){var k=
-v(g.value);g=k.next().value;k=k.next().value;e.push("--"+d+"\r\n");k instanceof Blob?e.push('Content-Disposition: form-data; name="'+g+'"; filename="'+k.name+'"\r\nContent-Type: '+((k.type||"application/octet-stream")+"\r\n\r\n"),k,"\r\n"):e.push('Content-Disposition: form-data; name="'+g+'"\r\n\r\n'+k+"\r\n")}e.push("--"+d+"--");return new Blob(e,{type:"multipart/form-data; boundary="+d})};V.prototype[Symbol.iterator]=function(){return this.entries()};V.prototype.toString=function(){return"[object FormData]"};
+lastModified:{value:+(d&&void 0!==d.lastModified?new Date(d.lastModified):new Date)},toString:{value:function(){return"[object File]"}}});U&&Object.defineProperty(c,U,{value:"File"});return c}}var escape=function(a){return a.replace(/\n/g,"%0A").replace(/\r/g,"%0D").replace(/"/g,"%22")},V=function(a){this.i=[];var c=this;a&&L(a.elements,function(b){if(b.name&&!b.disabled&&"submit"!==b.type&&"button"!==b.type&&!b.matches("form fieldset[disabled] *"))if("file"===b.type){var d=b.files&&b.files.length?
+b.files:[new File([],"",{type:"application/octet-stream"})];L(d,function(e){c.append(b.name,e)})}else"select-multiple"===b.type||"select-one"===b.type?L(b.options,function(e){!e.disabled&&e.selected&&c.append(b.name,e.value)}):"checkbox"===b.type||"radio"===b.type?b.checked&&c.append(b.name,b.value):(d="textarea"===b.type?b.value.replace(/\r\n/g,"\n").replace(/\n/g,"\r\n"):b.value,c.append(b.name,d))})};h=V.prototype;h.append=function(a,c,b){N(arguments,2);this.i.push(M(a,c,b))};h["delete"]=function(a){N(arguments,
+1);var c=[];a=String(a);L(this.i,function(b){b[0]!==a&&c.push(b)});this.i=c};h.entries=function c(){var b,d=this;return K(c,function(e){1==e.h&&(b=0);if(3!=e.h)return b<d.i.length?e=E(e,d.i[b]):(e.h=0,e=void 0),e;b++;e.h=2})};h.forEach=function(c,b){N(arguments,1);for(var d=v(this),e=d.next();!e.done;e=d.next()){var f=v(e.value);e=f.next().value;f=f.next().value;c.call(b,f,e,this)}};h.get=function(c){N(arguments,1);var b=this.i;c=String(c);for(var d=0;d<b.length;d++)if(b[d][0]===c)return b[d][1];
+return null};h.getAll=function(c){N(arguments,1);var b=[];c=String(c);L(this.i,function(d){d[0]===c&&b.push(d[1])});return b};h.has=function(c){N(arguments,1);c=String(c);for(var b=0;b<this.i.length;b++)if(this.i[b][0]===c)return!0;return!1};h.keys=function b(){var d=this,e,f,g,k,p;return K(b,function(t){1==t.h&&(e=v(d),f=e.next());if(3!=t.h){if(f.done){t.h=0;return}g=f.value;k=v(g);p=k.next().value;return E(t,p)}f=e.next();t.h=2})};h.set=function(b,d,e){N(arguments,2);b=String(b);var f=[],g=M(b,
+d,e),k=!0;L(this.i,function(p){p[0]===b?k&&(k=!f.push(g)):f.push(p)});k&&f.push(g);this.i=f};h.values=function d(){var e=this,f,g,k,p,t;return K(d,function(x){1==x.h&&(f=v(e),g=f.next());if(3!=x.h){if(g.done){x.h=0;return}k=g.value;p=v(k);p.next();t=p.next().value;return E(x,t)}g=f.next();x.h=2})};V.prototype._asNative=function(){for(var d=new P,e=v(this),f=e.next();!f.done;f=e.next()){var g=v(f.value);f=g.next().value;g=g.next().value;d.append(f,g)}return d};V.prototype._blob=function(){var d="----formdata-polyfill-"+
+Math.random(),e=[],f="--"+d+'\r\nContent-Disposition: form-data; name="';this.forEach(function(g,k){return"string"==typeof g?e.push(f+escape(k)+('"\r\n\r\n'+g+"\r\n")):e.push(f+escape(k)+('"; filename="'+escape(g.name)+'"\r\nContent-Type: '+(g.type||"application/octet-stream")+"\r\n\r\n"),g,"\r\n")});e.push("--"+d+"--");return new Blob(e,{type:"multipart/form-data; boundary="+d})};V.prototype[Symbol.iterator]=function(){return this.entries()};V.prototype.toString=function(){return"[object FormData]"};
 T&&!T.matches&&(T.matches=T.matchesSelector||T.mozMatchesSelector||T.msMatchesSelector||T.oMatchesSelector||T.webkitMatchesSelector||function(d){d=(this.document||this.ownerDocument).querySelectorAll(d);for(var e=d.length;0<=--e&&d.item(e)!==this;);return-1<e});U&&(V.prototype[U]="FormData");if(Q){var W=O.XMLHttpRequest.prototype.setRequestHeader;O.XMLHttpRequest.prototype.setRequestHeader=function(d,e){W.call(this,d,e);"content-type"===d.toLowerCase()&&(this.B=!0)};O.XMLHttpRequest.prototype.send=
 function(d){d instanceof V?(d=d._blob(),this.B||this.setRequestHeader("Content-Type",d.type),Q.call(this,d)):Q.call(this,d)}}R&&(O.fetch=function(d,e){e&&e.body&&e.body instanceof V&&(e.body=e.body._blob());return R.call(this,d,e)});S&&(O.navigator.sendBeacon=function(d,e){e instanceof V&&(e=e._asNative());return S.call(this,d,e)});O.FormData=V};
 })();
diff --git a/package.json b/package.json
index c595c8c..21b4795 100644
--- a/package.json
+++ b/package.json
@@ -1,13 +1,13 @@
 {
   "name": "formdata-polyfill",
-  "version": "4.0.3",
+  "version": "4.0.4",
   "description": "HTML5 `FormData` for Browsers and Node.",
   "type": "module",
   "main": "formdata.min.js",
   "scripts": {
     "build": "node build",
-    "_prepare": "npm run build && npm run test",
-    "_test": "karma start --single-run --browsers ChromeHeadless karma.conf.js"
+    "prepare": "npm run build && npm run test",
+    "test": "node test/test-esm.js"
   },
   "repository": {
     "type": "git",
diff --git a/test/test-esm.js b/test/test-esm.js
index 5dc4524..405d321 100644
--- a/test/test-esm.js
+++ b/test/test-esm.js
@@ -1,5 +1,6 @@
 import Blob from 'fetch-blob'
-import {FormData, formDataToBlob, File} from '../esm.min.js'
+import File from 'fetch-blob/file.js'
+import {FormData, formDataToBlob} from '../esm.min.js'
 
 console.assert(
   formDataToBlob(createFormData(['key', 'value1'])).size > 100,
@@ -38,6 +39,21 @@ for (let x of [undefined, null, 0, '', {}, false, true, globalThis, NaN]) {
   )
 }
 
+
+// #120 escapes keys when encoding FormData
+for (let [key, expected] of [['key\n', 'key%0A'], ['key\r', 'key%0D'], ['key"', 'key%22']]) {
+  const fd = createFormData([key, 'value'])
+  const str = await formDataToBlob(fd).text()
+  console.assert(str.includes(expected) === true)
+}
+
+// #120 escapes filename encoding FormData
+for (let [filename, expected] of [['val\nue', 'val%0Aue'], ['val%0Aue', 'val%0Aue']]) {
+  const fd = createFormData(['key', new File([], filename)])
+  const str = await formDataToBlob(fd).text()
+  console.assert(str.includes(expected))
+}
+
 {
   // Appending a empty blob with a name should convert it to a File
   var val = createFormData(['key', new Blob(), 'blank.txt']).get('key')
diff --git a/test/test-polyfill.html b/test/test-polyfill.html
index f0144be..c4127ef 100644
--- a/test/test-polyfill.html
+++ b/test/test-polyfill.html
@@ -12,14 +12,16 @@
 </script>
 <!-- <script src="../formdata.min.js"></script> -->
 <script src="../FormData.js"></script>
-<script>
+<script type="module">
+  import {formDataToBlob} from '../formdata-to-blob.js'
+
   const Polyfill = globalThis.FormData
 
   function catchErr(fn) {
     try { fn() } catch (err) { return err }
   }
 
-  ;[NativeFormData, Polyfill].map(async FormData => {
+  for (const FormData of [NativeFormData, Polyfill]) {
     function createFormData (...args) {
       const fd = new FormData()
       for (const arg of args) {
@@ -42,6 +44,34 @@
       console.assert(err instanceof TypeError, 'should throw on few arguments')
     }
 
+    // #120 escapes keys when encoding FormData
+    for (let [key, expected] of [['key\n', 'key%0A'], ['key\r', 'key%0D'], ['key"', 'key%22']]) {
+      const origFd = createFormData([key, 'value'])
+      const fd = await new Response(origFd._blob ? origFd._blob() : origFd).formData()
+      console.assert(fd.has(expected) === true)
+    }
+
+    // #120 escapes filename encoding FormData
+    for (let [filename, expected] of [['val\nue', 'val%0Aue'], ['val%0Aue', 'val%0Aue']]) {
+      const origFd = createFormData(['key', new NativeFile([], filename)])
+      const fd = await new Response(origFd._blob ? origFd._blob() : origFd).formData()
+      console.assert(fd.get('key').name === expected)
+    }
+
+    // #120 escapes keys when encoding FormData
+    for (let [key, expected] of [['key\n', 'key%0A'], ['key\r', 'key%0D'], ['key"', 'key%22']]) {
+      const blob = formDataToBlob(createFormData([key, 'value']))
+      const fd = await new Response(blob).formData()
+      console.assert(fd.has(expected) === true)
+    }
+
+    // #120 escapes filename encoding FormData
+    for (let [filename, expected] of [['val\nue', 'val%0Aue'], ['val%0Aue', 'val%0Aue']]) {
+      const blob = formDataToBlob(createFormData(['key', new NativeFile([], filename)]))
+      const fd = await new Response(blob).formData()
+      console.assert(fd.get('key').name === expected)
+    }
+
     // #78
     {
       const fd = createForm(`<input name=foo type=file>`)
@@ -296,7 +326,7 @@
       {
         const fd = createFormData(['key', '\n'])
         const value = fd.get('key')
-        console.assert('\n', value, 'Should not convert LF to CRLF when provided by append')
+        console.assert('\n' === value, 'Should not convert LF to CRLF when provided by append')
       }
 
       {
@@ -379,5 +409,5 @@
       }
       xhr.send(formData)
     }
-  })
+  }
 </script>