diff --git a/Build/Sources/TypeScript/core/Resources/Public/TypeScript/Ajax/InputTransformer.ts b/Build/Sources/TypeScript/core/Resources/Public/TypeScript/Ajax/InputTransformer.ts
index dda212455d3c32d3d9bac12f79d9c3dd50b0a774..46dc636551d217e3ccb3144dc91bf149adc9f950 100644
--- a/Build/Sources/TypeScript/core/Resources/Public/TypeScript/Ajax/InputTransformer.ts
+++ b/Build/Sources/TypeScript/core/Resources/Public/TypeScript/Ajax/InputTransformer.ts
@@ -35,7 +35,7 @@ export class InputTransformer {
    * @return {FormData}
    */
   public static toFormData(data: GenericKeyValue): FormData {
-    const flattenedData = InputTransformer.flattenObject(data);
+    const flattenedData = InputTransformer.filter(InputTransformer.flattenObject(data));
     const formData = new FormData();
     for (const [key, value] of Object.entries(flattenedData)) {
       formData.set(key, value);
@@ -59,7 +59,7 @@ export class InputTransformer {
       return data.join('&');
     }
 
-    const flattenedData = InputTransformer.flattenObject(data);
+    const flattenedData = InputTransformer.filter(InputTransformer.flattenObject(data));
     const searchParams = new URLSearchParams();
     for (const [key, value] of Object.entries(flattenedData)) {
       searchParams.set(key, value);
@@ -80,4 +80,13 @@ export class InputTransformer {
       return accumulator;
     }, {});
   }
+
+  private static filter(obj: GenericKeyValue): GenericKeyValue {
+    Object.keys(obj).forEach((key: string): void => {
+      if (typeof obj[key] === 'undefined') {
+        delete obj[key];
+      }
+    });
+    return obj;
+  }
 }
diff --git a/Build/Sources/TypeScript/core/Tests/Ajax/InputTransformerTest.ts b/Build/Sources/TypeScript/core/Tests/Ajax/InputTransformerTest.ts
new file mode 100644
index 0000000000000000000000000000000000000000..5906d92483d0976d260361a0b018f9f3d90b4b97
--- /dev/null
+++ b/Build/Sources/TypeScript/core/Tests/Ajax/InputTransformerTest.ts
@@ -0,0 +1,62 @@
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+import {GenericKeyValue, InputTransformer} from 'TYPO3/CMS/Core/Ajax/InputTransformer';
+
+describe('TYPO3/CMS/Core/Ajax/InputTransformer', (): void => {
+  it('converts object to FormData', (): void => {
+    const input: GenericKeyValue = {foo: 'bar', bar: 'baz', nested: {works: 'yes'}};
+    const expected = new FormData();
+    expected.set('foo', 'bar');
+    expected.set('bar', 'baz');
+    expected.set('nested[works]', 'yes');
+
+    expect(InputTransformer.toFormData(input)).toEqual(expected);
+  });
+
+  it('undefined values are removed in FormData', (): void => {
+    const input: GenericKeyValue = {foo: 'bar', bar: 'baz', removeme: undefined};
+    const expected = new FormData();
+    expected.set('foo', 'bar');
+    expected.set('bar', 'baz');
+
+    expect(InputTransformer.toFormData(input)).toEqual(expected);
+  });
+
+  it('converts object to SearchParams', (): void => {
+    const input: GenericKeyValue = {foo: 'bar', bar: 'baz', nested: {works: 'yes'}};
+    const expected = 'foo=bar&bar=baz&nested[works]=yes';
+
+    expect(InputTransformer.toSearchParams(input)).toEqual(expected);
+  });
+
+  it('merges array to SearchParams', (): void => {
+    const input: Array<string> = ['foo=bar', 'bar=baz'];
+    const expected = 'foo=bar&bar=baz';
+
+    expect(InputTransformer.toSearchParams(input)).toEqual(expected);
+  });
+
+  it('keeps string in SearchParams', (): void => {
+    const input: string = 'foo=bar&bar=baz';
+    const expected = 'foo=bar&bar=baz';
+
+    expect(InputTransformer.toSearchParams(input)).toEqual(expected);
+  });
+
+  it('undefined values are removed in SearchParams', (): void => {
+    const input: GenericKeyValue = {foo: 'bar', bar: 'baz', removeme: undefined};
+    const expected = 'foo=bar&bar=baz';
+    expect(InputTransformer.toSearchParams(input)).toEqual(expected);
+  });
+});
diff --git a/typo3/sysext/core/Resources/Public/JavaScript/Ajax/InputTransformer.js b/typo3/sysext/core/Resources/Public/JavaScript/Ajax/InputTransformer.js
index dd8b065e77f1815c03d8a0ccacc6b71712220ee8..bd79c10592913dc1c7dc13c8efdcec7f081f70fb 100644
--- a/typo3/sysext/core/Resources/Public/JavaScript/Ajax/InputTransformer.js
+++ b/typo3/sysext/core/Resources/Public/JavaScript/Ajax/InputTransformer.js
@@ -10,4 +10,4 @@
  *
  * The TYPO3 project - inspiring people to share!
  */
-define(["require","exports"],(function(t,e){"use strict";Object.defineProperty(e,"__esModule",{value:!0});class n{static byHeader(t,e={}){return e.hasOwnProperty("Content-Type")&&e["Content-Type"].includes("application/json")?JSON.stringify(t):n.toFormData(t)}static toFormData(t){const e=n.flattenObject(t),r=new FormData;for(const[t,n]of Object.entries(e))r.set(t,n);return r}static toSearchParams(t){if("string"==typeof t)return t;if(t instanceof Array)return t.join("&");const e=n.flattenObject(t),r=new URLSearchParams;for(const[t,n]of Object.entries(e))r.set(t,n);return decodeURI(r.toString())}static flattenObject(t,e=""){return Object.keys(t).reduce((r,o)=>{const s=e.length?e+"[":"",a=e.length?"]":"";return"object"==typeof t[o]?Object.assign(r,n.flattenObject(t[o],s+o+a)):r[s+o+a]=t[o],r},{})}}e.InputTransformer=n}));
\ No newline at end of file
+define(["require","exports"],(function(t,e){"use strict";Object.defineProperty(e,"__esModule",{value:!0});class r{static byHeader(t,e={}){return e.hasOwnProperty("Content-Type")&&e["Content-Type"].includes("application/json")?JSON.stringify(t):r.toFormData(t)}static toFormData(t){const e=r.filter(r.flattenObject(t)),n=new FormData;for(const[t,r]of Object.entries(e))n.set(t,r);return n}static toSearchParams(t){if("string"==typeof t)return t;if(t instanceof Array)return t.join("&");const e=r.filter(r.flattenObject(t)),n=new URLSearchParams;for(const[t,r]of Object.entries(e))n.set(t,r);return decodeURI(n.toString())}static flattenObject(t,e=""){return Object.keys(t).reduce((n,o)=>{const s=e.length?e+"[":"",a=e.length?"]":"";return"object"==typeof t[o]?Object.assign(n,r.flattenObject(t[o],s+o+a)):n[s+o+a]=t[o],n},{})}static filter(t){return Object.keys(t).forEach(e=>{void 0===t[e]&&delete t[e]}),t}}e.InputTransformer=r}));
\ No newline at end of file
diff --git a/typo3/sysext/core/Tests/JavaScript/Ajax/InputTransformerTest.js b/typo3/sysext/core/Tests/JavaScript/Ajax/InputTransformerTest.js
new file mode 100644
index 0000000000000000000000000000000000000000..0486e5af0a6ad33c8d3226852ea4110f2e480796
--- /dev/null
+++ b/typo3/sysext/core/Tests/JavaScript/Ajax/InputTransformerTest.js
@@ -0,0 +1,13 @@
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+define(["require","exports","TYPO3/CMS/Core/Ajax/InputTransformer"],(function(a,r,e){"use strict";Object.defineProperty(r,"__esModule",{value:!0}),describe("TYPO3/CMS/Core/Ajax/InputTransformer",()=>{it("converts object to FormData",()=>{const a=new FormData;a.set("foo","bar"),a.set("bar","baz"),a.set("nested[works]","yes"),expect(e.InputTransformer.toFormData({foo:"bar",bar:"baz",nested:{works:"yes"}})).toEqual(a)}),it("undefined values are removed in FormData",()=>{const a={foo:"bar",bar:"baz",removeme:void 0},r=new FormData;r.set("foo","bar"),r.set("bar","baz"),expect(e.InputTransformer.toFormData(a)).toEqual(r)}),it("converts object to SearchParams",()=>{expect(e.InputTransformer.toSearchParams({foo:"bar",bar:"baz",nested:{works:"yes"}})).toEqual("foo=bar&bar=baz&nested[works]=yes")}),it("merges array to SearchParams",()=>{expect(e.InputTransformer.toSearchParams(["foo=bar","bar=baz"])).toEqual("foo=bar&bar=baz")}),it("keeps string in SearchParams",()=>{expect(e.InputTransformer.toSearchParams("foo=bar&bar=baz")).toEqual("foo=bar&bar=baz")}),it("undefined values are removed in SearchParams",()=>{const a={foo:"bar",bar:"baz",removeme:void 0};expect(e.InputTransformer.toSearchParams(a)).toEqual("foo=bar&bar=baz")})})}));
\ No newline at end of file