diff --git a/package-lock.json b/package-lock.json
index 732df91..139f4f4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -777,6 +777,12 @@
       "integrity": "sha1-7ihweulOEdK4J7y+UnC86n8+ce4=",
       "dev": true
     },
+    "@types/mime-types": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/@types/mime-types/-/mime-types-2.1.0.tgz",
+      "integrity": "sha1-nKUs2jY/aZxpRmwqbM2q2RPqenM=",
+      "dev": true
+    },
     "@types/minimist": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/@types/minimist/-/minimist-1.2.0.tgz",
@@ -4307,6 +4313,19 @@
       "integrity": "sha512-RZKhC3EmpBchfTGBVb8fb+RL2cWyw/32lshnsETttkBAyAUXSGHxbEJWWRXc751DrIxG1q04b8QwMbAwkRPpUA==",
       "dev": true
     },
+    "mime-db": {
+      "version": "1.44.0",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.44.0.tgz",
+      "integrity": "sha512-/NOTfLrsPBVeH7YtFPgsVWveuL+4SjjYxaQ1xtM1KMFj7HdxlBlxeyNLzhyJVx7r4rZGJAZ/6lkKCitSc/Nmpg=="
+    },
+    "mime-types": {
+      "version": "2.1.27",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.27.tgz",
+      "integrity": "sha512-JIhqnCasI9yD+SsmkquHBxTSEuZdQX5BuQnS2Vc7puQQQ+8yiP5AY5uWhpdv4YL4VM5c6iliiYWPgJ/nJQLp7w==",
+      "requires": {
+        "mime-db": "1.44.0"
+      }
+    },
     "mimic-fn": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/mimic-fn/-/mimic-fn-2.1.0.tgz",
diff --git a/package.json b/package.json
index a4ea752..adfac8f 100644
--- a/package.json
+++ b/package.json
@@ -56,6 +56,7 @@
   "homepage": "https://github.com/NeuraLegion/postman2har#readme",
   "dependencies": {
     "faker": "^4.1.0",
+    "mime-types": "^2.1.27",
     "semver": "^7.3.2",
     "tslib": "~1.11.1"
   },
@@ -67,6 +68,7 @@
     "@types/debug": "^4.1.5",
     "@types/faker": "^4.1.12",
     "@types/har-format": "^1.2.4",
+    "@types/mime-types": "^2.1.0",
     "@types/mocha": "~7.0.2",
     "@types/node": "~14.0.13",
     "@types/semver": "^7.3.1",
diff --git a/src/converter/DefaultConverter.ts b/src/converter/DefaultConverter.ts
index 335409a..a672057 100644
--- a/src/converter/DefaultConverter.ts
+++ b/src/converter/DefaultConverter.ts
@@ -2,9 +2,11 @@ import { Converter } from './Converter';
 import { Validator } from '../validator';
 import { VariableParser, VariableParserFactory } from '../parser';
 import Har from 'har-format';
+import { lookup } from 'mime-types';
 import { ok } from 'assert';
 import { format, parse, UrlObject } from 'url';
 import { parse as parseQS, ParsedUrlQuery, stringify } from 'querystring';
+import { basename, extname } from 'path';
 
 enum AuthLocation {
   QUERY = 'queryString',
@@ -83,7 +85,7 @@ export class DefaultConverter implements Converter {
       const request: Har.Request = {
         url,
         method: (method ?? 'GET').toUpperCase(),
-        headers: this.convertHeaders(header!, variables),
+        headers: this.convertHeaders(header ?? '', variables),
         queryString: this.convertQuery(url, variables),
         cookies: [],
         postData: body && this.convertBody(body, variables),
@@ -308,11 +310,25 @@ export class DefaultConverter implements Converter {
     return {
       mimeType: 'multipart/form-data',
       params: Array.isArray(body.formdata)
-        ? body.formdata.map((x: Postman.FormParam) => ({
-            name: parser.parse(x.key ?? ''),
-            value: parser.parse(x.value ?? ''),
-            contentType: x.contentType
-          }))
+        ? body.formdata.map((x: Postman.FormParam) => {
+            const fileName: string | undefined = x.src
+              ? basename(Array.isArray(x.src) ? x.src.pop()! : x.src)
+              : undefined;
+
+            const extension: string | undefined = fileName
+              ? extname(fileName)
+              : fileName;
+
+            const contentType: string | undefined =
+              x.contentType ?? (lookup(extension ?? '') || undefined);
+
+            return {
+              fileName,
+              contentType,
+              name: parser.parse(x.key ?? ''),
+              value: parser.parse(x.value ?? '')
+            };
+          })
         : [],
       text: ''
     };
@@ -330,7 +346,7 @@ export class DefaultConverter implements Converter {
         value: parser.parse(x.value ?? '')
       }));
     } else {
-      params = Object.entries(parseQS(body.urlencoded!)).map(
+      params = Object.entries(parseQS(body.urlencoded ?? '')).map(
         ([name, value]) => ({
           name,
           value: Array.isArray(value) ? value.join('&') : value
@@ -343,7 +359,7 @@ export class DefaultConverter implements Converter {
         ? body.urlencoded
         : stringify(
             Object.fromEntries(
-              body.urlencoded!.map((x: Postman.QueryParam) => [
+              (body.urlencoded ?? []).map((x: Postman.QueryParam) => [
                 parser.parse(x.key ?? ''),
                 parser.parse(x.value ?? '')
               ])