diff --git a/dev/test-studio/schema/debug/patchOnMount.tsx b/dev/test-studio/schema/debug/patchOnMount.tsx
new file mode 100644
index 00000000000..1595b5317bb
--- /dev/null
+++ b/dev/test-studio/schema/debug/patchOnMount.tsx
@@ -0,0 +1,30 @@
+import {defineType} from '@sanity/types'
+import {useEffect, useRef} from 'react'
+import {set} from 'sanity'
+
+export const patchOnMountDebug = defineType({
+  type: 'document',
+  name: 'patchOnMountDebug',
+  fields: [
+    {
+      type: 'string',
+      name: 'title',
+    },
+  ],
+  components: {
+    // eslint-disable-next-line func-name-matching
+    input: function PatchOnMountInput(props) {
+      const {onChange} = props
+      const mounted = useRef(false)
+
+      useEffect(() => {
+        if (!mounted.current) {
+          onChange(set(`${Math.random()}`, ['title']))
+          mounted.current = true
+        }
+      }, [onChange])
+
+      return props.renderDefault(props)
+    },
+  },
+})
diff --git a/dev/test-studio/schema/index.ts b/dev/test-studio/schema/index.ts
index b579539513f..ebc53f54904 100644
--- a/dev/test-studio/schema/index.ts
+++ b/dev/test-studio/schema/index.ts
@@ -53,6 +53,7 @@ import localeString from './debug/localeString'
 import manyFieldsTest from './debug/manyFieldsTest'
 import notitle from './debug/notitle'
 import {objectsDebug} from './debug/objectsDebug'
+import {patchOnMountDebug} from './debug/patchOnMount'
 import poppers from './debug/poppers'
 import presence, {objectWithNestedArray} from './debug/presence'
 import previewImageUrlTest from './debug/previewImageUrlTest'
@@ -238,6 +239,7 @@ export const schemaTypes = [
   recursiveObjectTest,
   recursiveObject,
   recursivePopover,
+  patchOnMountDebug,
   simpleArrayOfObjects,
   simpleReferences,
   reservedFieldNames,
diff --git a/dev/test-studio/structure/constants.ts b/dev/test-studio/structure/constants.ts
index ffcdea6447a..75b4b5ba8e5 100644
--- a/dev/test-studio/structure/constants.ts
+++ b/dev/test-studio/structure/constants.ts
@@ -55,6 +55,7 @@ export const DEBUG_INPUT_TYPES = [
   'fieldsetsTest',
   'fieldValidationInferReproDoc',
   'focusTest',
+  'patchOnMountDebug',
   'formInputDebug',
   'initialValuesTest',
   'inspectorsTest',