diff --git a/packages/server/package.json b/packages/server/package.json
index 96dea7231..c40be70cb 100644
--- a/packages/server/package.json
+++ b/packages/server/package.json
@@ -34,7 +34,7 @@
     "bulma-prefers-dark": "0.1.0-beta.1",
     "compare-versions": "6.1.0",
     "dayjs": "1.11.10",
-    "formidable": "3.5.1",
+    "formidable": "2.1.2",
     "fs-extra": "11.2.0",
     "html-entities": "1.4.0",
     "jquery": "3.7.1",
@@ -63,7 +63,7 @@
     "@joplin/tools": "~2.14",
     "@rmp135/sql-ts": "1.18.1",
     "@types/bcryptjs": "2.4.6",
-    "@types/formidable": "3.4.5",
+    "@types/formidable": "2.0.6",
     "@types/fs-extra": "11.0.4",
     "@types/jest": "29.5.8",
     "@types/jest-expect-message": "1.0.4",
diff --git a/packages/server/src/utils/requestUtils.ts b/packages/server/src/utils/requestUtils.ts
index bd15633d8..b04516186 100644
--- a/packages/server/src/utils/requestUtils.ts
+++ b/packages/server/src/utils/requestUtils.ts
@@ -1,12 +1,10 @@
 import { cookieGet } from './cookies';
 import { ErrorForbidden } from './errors';
 import { AppContext } from './types';
-import * as formidableFn from 'formidable';
+import * as formidable from 'formidable';
 import { Fields, Files } from 'formidable';
 import { IncomingMessage } from 'http';
 
-const formidable = require('formidable').default as typeof formidableFn;
-
 export type BodyFields = Record<string, any>;
 
 interface FormParseResult {
@@ -26,16 +24,17 @@ interface FormParseRequest extends IncomingMessage {
 	body: any;
 }
 
-// Previously Formidable would return the files and fields as key/value pairs.
-// With v3, the value however is always an array. This is unclear why they did
-// this but for example a field `email=test@example.com` would come out as
-// `email: ['test@example.com']`. Since all our code expect simple key/value
-// pairs, we use this function to convert back to the old style.
+// Previously Formidable would return the files and fields as key/value pairs. With v3, the value
+// however is always an array. This is unclear why they did this but for example a field
+// `email=test@example.com` would come out as `email: ['test@example.com']`. Since all our code
+// expect simple key/value pairs, we use this function to convert back to the old style.
 //
 // For the extra challenge, they made this change only if the content-type is
-// "application/x-www-form-urlencoded". Other content types such as JSON are not
-// modified.
-const convertFieldsToKeyValue = (fields: Record<string, any[]>) => {
+// "application/x-www-form-urlencoded". Other content types such as JSON are not modified.
+//
+// As of 2024-01-18, this may no longer be necessary since we reverted to Formidable v2, but keeping
+// it anyway just in case.
+const convertFieldsToKeyValue = (fields: Files | Fields) => {
 	const convertedFields: Record<string, any> = {};
 	for (const [k, v] of Object.entries(fields)) {
 		if (Array.isArray(v)) {
diff --git a/renovate.json5 b/renovate.json5
index 45f350dbb..3a102b813 100644
--- a/renovate.json5
+++ b/renovate.json5
@@ -135,6 +135,11 @@
 		"strip-ansi",
 		"node-emoji",
 
+		// Formidable v3 is broken:
+		// https://github.com/node-formidable/formidable/issues/958
+		"formidable",
+		"@types/formidable",
+
 		// @koa/cors has undocumented breaking changes, and the package is not
 		// well supported so we're stuck with latest v3 for now
 		"@koa/cors",
diff --git a/yarn.lock b/yarn.lock
index 0a7a7e59f..b3d09b191 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -7045,7 +7045,7 @@ __metadata:
     "@koa/cors": 3.4.3
     "@rmp135/sql-ts": 1.18.1
     "@types/bcryptjs": 2.4.6
-    "@types/formidable": 3.4.5
+    "@types/formidable": 2.0.6
     "@types/fs-extra": 11.0.4
     "@types/jest": 29.5.8
     "@types/jest-expect-message": 1.0.4
@@ -7062,7 +7062,7 @@ __metadata:
     bulma-prefers-dark: 0.1.0-beta.1
     compare-versions: 6.1.0
     dayjs: 1.11.10
-    formidable: 3.5.1
+    formidable: 2.1.2
     fs-extra: 11.2.0
     gulp: 4.0.2
     html-entities: 1.4.0
@@ -10415,12 +10415,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/formidable@npm:3.4.5":
-  version: 3.4.5
-  resolution: "@types/formidable@npm:3.4.5"
+"@types/formidable@npm:2.0.6":
+  version: 2.0.6
+  resolution: "@types/formidable@npm:2.0.6"
   dependencies:
     "@types/node": "*"
-  checksum: 27384c8459e44f5e167922927bd31fcd1259555062faacaa490b52f8896a0a5614918ee4ec6ec9123c1418ac127908270c1182a2441d49681b37dc34737c3646
+  checksum: d6be0ac12bf8dd2e4f8a022271ee6e501c7f6d7dd58d71c68497ca7da84bee1538d1a2a64a90b56dad557ddb291d48c5731206269e9ab53ed91264e68a4d1476
   languageName: node
   linkType: hard
 
@@ -21857,14 +21857,15 @@ __metadata:
   languageName: node
   linkType: hard
 
-"formidable@npm:3.5.1":
-  version: 3.5.1
-  resolution: "formidable@npm:3.5.1"
+"formidable@npm:2.1.2":
+  version: 2.1.2
+  resolution: "formidable@npm:2.1.2"
   dependencies:
     dezalgo: ^1.0.4
     hexoid: ^1.0.0
     once: ^1.4.0
-  checksum: 46b21496f9f985161cf7636163147b6728f9997c7e1d59433680d92619758bf6862330e6d105b5816bafcd1ab32f27ef183455991f93ef836ea731c68db62af9
+    qs: ^6.11.0
+  checksum: 81c8e5d89f5eb873e992893468f0de22c01678ca3d315db62be0560f9de1c77d4faefc9b1f4575098eb2263b3c81ba1024833a9fc3206297ddbac88a4f69b7a8
   languageName: node
   linkType: hard
 
@@ -34662,7 +34663,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"qs@npm:^6.11.2":
+"qs@npm:^6.11.0, qs@npm:^6.11.2":
   version: 6.11.2
   resolution: "qs@npm:6.11.2"
   dependencies: