diff --git a/packages/payload/src/errors/APIError.ts b/packages/payload/src/errors/APIError.ts
index 0c5048b4833..11144781ef4 100644
--- a/packages/payload/src/errors/APIError.ts
+++ b/packages/payload/src/errors/APIError.ts
@@ -1,7 +1,9 @@
 import { status as httpStatus } from 'http-status'
 
-// This gets dynamically reassigned during compilation
-export let APIErrorName = 'APIError'
+/**
+ * @deprecated Remove this in 4.0 - this is no longer needed as we assign the prototype correctly in the constructor
+ */
+export const APIErrorName = 'APIError'
 
 class ExtendableError<TData extends object = { [key: string]: unknown }> extends Error {
   data: TData
@@ -17,13 +19,17 @@ class ExtendableError<TData extends object = { [key: string]: unknown }> extends
       // show data in cause
       cause: data,
     })
-    APIErrorName = this.constructor.name
-    this.name = this.constructor.name
     this.message = message
     this.status = status
     this.data = data
     this.isPublic = isPublic
     this.isOperational = true // This is required since bluebird 4 doesn't append it anymore.
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'ExtendableError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, ExtendableError.prototype)
+
     Error.captureStackTrace(this, this.constructor)
   }
 }
@@ -50,5 +56,10 @@ export class APIError<
     isPublic = false,
   ) {
     super(message, status, data, isPublic)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'APIError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, APIError.prototype)
   }
 }
diff --git a/packages/payload/src/errors/AuthenticationError.ts b/packages/payload/src/errors/AuthenticationError.ts
index b756974ab99..582089ec50a 100644
--- a/packages/payload/src/errors/AuthenticationError.ts
+++ b/packages/payload/src/errors/AuthenticationError.ts
@@ -13,5 +13,10 @@ export class AuthenticationError extends APIError {
         : en.translations.error.emailOrPasswordIncorrect,
       httpStatus.UNAUTHORIZED,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'AuthenticationError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, AuthenticationError.prototype)
   }
 }
diff --git a/packages/payload/src/errors/DuplicateCollection.ts b/packages/payload/src/errors/DuplicateCollection.ts
index e2f97b493de..14a1b1d1fd6 100644
--- a/packages/payload/src/errors/DuplicateCollection.ts
+++ b/packages/payload/src/errors/DuplicateCollection.ts
@@ -3,5 +3,10 @@ import { APIError } from './APIError.js'
 export class DuplicateCollection extends APIError {
   constructor(propertyName: string, duplicate: string) {
     super(`Collection ${propertyName} already in use: "${duplicate}"`)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'DuplicateCollection'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, DuplicateCollection.prototype)
   }
 }
diff --git a/packages/payload/src/errors/DuplicateFieldName.ts b/packages/payload/src/errors/DuplicateFieldName.ts
index 4760415c385..158e51269c2 100644
--- a/packages/payload/src/errors/DuplicateFieldName.ts
+++ b/packages/payload/src/errors/DuplicateFieldName.ts
@@ -5,5 +5,10 @@ export class DuplicateFieldName extends APIError {
     super(
       `A field with the name '${fieldName}' was found multiple times on the same level. Field names must be unique.`,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'DuplicateFieldName'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, DuplicateFieldName.prototype)
   }
 }
diff --git a/packages/payload/src/errors/DuplicateGlobal.ts b/packages/payload/src/errors/DuplicateGlobal.ts
index a12e66ad5a5..e4b35cbebbf 100644
--- a/packages/payload/src/errors/DuplicateGlobal.ts
+++ b/packages/payload/src/errors/DuplicateGlobal.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class DuplicateGlobal extends APIError {
   constructor(config: GlobalConfig) {
     super(`Global label "${config.label}" is already in use`)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'DuplicateGlobal'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, DuplicateGlobal.prototype)
   }
 }
diff --git a/packages/payload/src/errors/ErrorDeletingFile.ts b/packages/payload/src/errors/ErrorDeletingFile.ts
index 01ef0e78004..b6d83ee14b2 100644
--- a/packages/payload/src/errors/ErrorDeletingFile.ts
+++ b/packages/payload/src/errors/ErrorDeletingFile.ts
@@ -11,5 +11,10 @@ export class ErrorDeletingFile extends APIError {
       t ? t('error:deletingFile') : en.translations.error.deletingFile,
       httpStatus.INTERNAL_SERVER_ERROR,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'ErrorDeletingFile'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, ErrorDeletingFile.prototype)
   }
 }
diff --git a/packages/payload/src/errors/FileRetrievalError.ts b/packages/payload/src/errors/FileRetrievalError.ts
index 51d881fe0e4..9598a532e85 100644
--- a/packages/payload/src/errors/FileRetrievalError.ts
+++ b/packages/payload/src/errors/FileRetrievalError.ts
@@ -12,5 +12,10 @@ export class FileRetrievalError extends APIError {
       msg += ` ${message}`
     }
     super(msg, httpStatus.INTERNAL_SERVER_ERROR)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'FileRetrievalError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, FileRetrievalError.prototype)
   }
 }
diff --git a/packages/payload/src/errors/FileUploadError.ts b/packages/payload/src/errors/FileUploadError.ts
index 11ada9350f9..77d6254b9fc 100644
--- a/packages/payload/src/errors/FileUploadError.ts
+++ b/packages/payload/src/errors/FileUploadError.ts
@@ -11,5 +11,10 @@ export class FileUploadError extends APIError {
       t ? t('error:problemUploadingFile') : en.translations.error.problemUploadingFile,
       httpStatus.BAD_REQUEST,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'FileUploadError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, FileUploadError.prototype)
   }
 }
diff --git a/packages/payload/src/errors/Forbidden.ts b/packages/payload/src/errors/Forbidden.ts
index 35beba489f1..df9b4639a1c 100644
--- a/packages/payload/src/errors/Forbidden.ts
+++ b/packages/payload/src/errors/Forbidden.ts
@@ -11,5 +11,10 @@ export class Forbidden extends APIError {
       t ? t('error:notAllowedToPerformAction') : en.translations.error.notAllowedToPerformAction,
       httpStatus.FORBIDDEN,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'Forbidden'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, Forbidden.prototype)
   }
 }
diff --git a/packages/payload/src/errors/InvalidConfiguration.ts b/packages/payload/src/errors/InvalidConfiguration.ts
index 7d0b53e18f8..f65070eac67 100644
--- a/packages/payload/src/errors/InvalidConfiguration.ts
+++ b/packages/payload/src/errors/InvalidConfiguration.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class InvalidConfiguration extends APIError {
   constructor(message: string) {
     super(message, httpStatus.INTERNAL_SERVER_ERROR)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'InvalidConfiguration'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, InvalidConfiguration.prototype)
   }
 }
diff --git a/packages/payload/src/errors/InvalidFieldJoin.ts b/packages/payload/src/errors/InvalidFieldJoin.ts
index fe29bcef8d4..400e942c995 100644
--- a/packages/payload/src/errors/InvalidFieldJoin.ts
+++ b/packages/payload/src/errors/InvalidFieldJoin.ts
@@ -7,5 +7,10 @@ export class InvalidFieldJoin extends APIError {
     super(
       `Invalid join field ${field.name}. The config does not have a field '${field.on}' in collection '${field.collection}'.`,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'InvalidFieldJoin'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, InvalidFieldJoin.prototype)
   }
 }
diff --git a/packages/payload/src/errors/InvalidFieldName.ts b/packages/payload/src/errors/InvalidFieldName.ts
index 3c45d0c5d5d..a348675b3d6 100644
--- a/packages/payload/src/errors/InvalidFieldName.ts
+++ b/packages/payload/src/errors/InvalidFieldName.ts
@@ -7,5 +7,10 @@ export class InvalidFieldName extends APIError {
     super(
       `Field ${field.label} has invalid name '${fieldName}'. Field names can not include periods (.) and must be alphanumeric.`,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'InvalidFieldName'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, InvalidFieldName.prototype)
   }
 }
diff --git a/packages/payload/src/errors/InvalidFieldRelationship.ts b/packages/payload/src/errors/InvalidFieldRelationship.ts
index 65e6f0fc177..def08f6e409 100644
--- a/packages/payload/src/errors/InvalidFieldRelationship.ts
+++ b/packages/payload/src/errors/InvalidFieldRelationship.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class InvalidFieldRelationship extends APIError {
   constructor(field: RelationshipField | UploadField, relationship: string) {
     super(`Field ${field.label} has invalid relationship '${relationship}'.`)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'InvalidFieldRelationship'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, InvalidFieldRelationship.prototype)
   }
 }
diff --git a/packages/payload/src/errors/InvalidSchema.ts b/packages/payload/src/errors/InvalidSchema.ts
index 78c5a4b4498..e0798b2b035 100644
--- a/packages/payload/src/errors/InvalidSchema.ts
+++ b/packages/payload/src/errors/InvalidSchema.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class InvalidSchema extends APIError {
   constructor(message: string, results: any) {
     super(message, httpStatus.INTERNAL_SERVER_ERROR, results)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'InvalidSchema'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, InvalidSchema.prototype)
   }
 }
diff --git a/packages/payload/src/errors/Locked.ts b/packages/payload/src/errors/Locked.ts
index 536c046f499..e50fd94ecdd 100644
--- a/packages/payload/src/errors/Locked.ts
+++ b/packages/payload/src/errors/Locked.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class Locked extends APIError {
   constructor(message: string) {
     super(message, httpStatus.LOCKED)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'Locked'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, Locked.prototype)
   }
 }
diff --git a/packages/payload/src/errors/LockedAuth.ts b/packages/payload/src/errors/LockedAuth.ts
index a2fa1bc40b5..5606d5ab0ab 100644
--- a/packages/payload/src/errors/LockedAuth.ts
+++ b/packages/payload/src/errors/LockedAuth.ts
@@ -8,5 +8,10 @@ import { APIError } from './APIError.js'
 export class LockedAuth extends APIError {
   constructor(t?: TFunction) {
     super(t ? t('error:userLocked') : en.translations.error.userLocked, httpStatus.UNAUTHORIZED)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'LockedAuth'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, LockedAuth.prototype)
   }
 }
diff --git a/packages/payload/src/errors/MissingCollectionLabel.ts b/packages/payload/src/errors/MissingCollectionLabel.ts
index ea8206635fe..c7be260c23e 100644
--- a/packages/payload/src/errors/MissingCollectionLabel.ts
+++ b/packages/payload/src/errors/MissingCollectionLabel.ts
@@ -3,5 +3,10 @@ import { APIError } from './APIError.js'
 export class MissingCollectionLabel extends APIError {
   constructor() {
     super('payload.config.collection object is missing label')
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'MissingCollectionLabel'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, MissingCollectionLabel.prototype)
   }
 }
diff --git a/packages/payload/src/errors/MissingEditorProp.ts b/packages/payload/src/errors/MissingEditorProp.ts
index 63adf9cf12d..87a630193a0 100644
--- a/packages/payload/src/errors/MissingEditorProp.ts
+++ b/packages/payload/src/errors/MissingEditorProp.ts
@@ -8,5 +8,10 @@ export class MissingEditorProp extends APIError {
     super(
       `RichText field${fieldAffectsData(field) ? ` "${field.name}"` : ''} is missing the editor prop. For sub-richText fields, the editor props is required, as it would otherwise create infinite recursion.`,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'MissingEditorProp'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, MissingEditorProp.prototype)
   }
 }
diff --git a/packages/payload/src/errors/MissingFieldInputOptions.ts b/packages/payload/src/errors/MissingFieldInputOptions.ts
index 7907598285e..22126307c8a 100644
--- a/packages/payload/src/errors/MissingFieldInputOptions.ts
+++ b/packages/payload/src/errors/MissingFieldInputOptions.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class MissingFieldInputOptions extends APIError {
   constructor(field: RadioField | SelectField) {
     super(`Field ${field.label} is missing options.`)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'MissingFieldInputOptions'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, MissingFieldInputOptions.prototype)
   }
 }
diff --git a/packages/payload/src/errors/MissingFieldType.ts b/packages/payload/src/errors/MissingFieldType.ts
index ab805c7b104..7e4e5ff35d3 100644
--- a/packages/payload/src/errors/MissingFieldType.ts
+++ b/packages/payload/src/errors/MissingFieldType.ts
@@ -10,5 +10,10 @@ export class MissingFieldType extends APIError {
         fieldAffectsData(field) ? ` "${field.name}"` : ''
       } is either missing a field type or it does not match an available field type`,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'MissingFieldType'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, MissingFieldType.prototype)
   }
 }
diff --git a/packages/payload/src/errors/MissingFile.ts b/packages/payload/src/errors/MissingFile.ts
index d8dcd3a9a2f..ffa9350632d 100644
--- a/packages/payload/src/errors/MissingFile.ts
+++ b/packages/payload/src/errors/MissingFile.ts
@@ -11,5 +11,10 @@ export class MissingFile extends APIError {
       t ? t('error:noFilesUploaded') : en.translations.error.noFilesUploaded,
       httpStatus.BAD_REQUEST,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'MissingFile'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, MissingFile.prototype)
   }
 }
diff --git a/packages/payload/src/errors/NotFound.ts b/packages/payload/src/errors/NotFound.ts
index 6f66f35ad68..b25c4681f4c 100644
--- a/packages/payload/src/errors/NotFound.ts
+++ b/packages/payload/src/errors/NotFound.ts
@@ -8,5 +8,10 @@ import { APIError } from './APIError.js'
 export class NotFound extends APIError {
   constructor(t?: TFunction) {
     super(t ? t('general:notFound') : en.translations.general.notFound, httpStatus.NOT_FOUND)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'NotFound'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, NotFound.prototype)
   }
 }
diff --git a/packages/payload/src/errors/QueryError.ts b/packages/payload/src/errors/QueryError.ts
index 2d891e6d3dc..bbad931b800 100644
--- a/packages/payload/src/errors/QueryError.ts
+++ b/packages/payload/src/errors/QueryError.ts
@@ -11,5 +11,10 @@ export class QueryError extends APIError<{ path: string }[]> {
       httpStatus.BAD_REQUEST,
       results,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'QueryError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, QueryError.prototype)
   }
 }
diff --git a/packages/payload/src/errors/ReservedFieldName.ts b/packages/payload/src/errors/ReservedFieldName.ts
index d9317fa96fa..0aedd2d30c9 100644
--- a/packages/payload/src/errors/ReservedFieldName.ts
+++ b/packages/payload/src/errors/ReservedFieldName.ts
@@ -5,5 +5,10 @@ import { APIError } from './APIError.js'
 export class ReservedFieldName extends APIError {
   constructor(field: FieldAffectingData, fieldName: string) {
     super(`Field ${field.label} has reserved name '${fieldName}'.`)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'ReservedFieldName'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, ReservedFieldName.prototype)
   }
 }
diff --git a/packages/payload/src/errors/TimestampsRequired.ts b/packages/payload/src/errors/TimestampsRequired.ts
index 0846f9fcd9e..818dbb5672d 100644
--- a/packages/payload/src/errors/TimestampsRequired.ts
+++ b/packages/payload/src/errors/TimestampsRequired.ts
@@ -7,5 +7,10 @@ export class TimestampsRequired extends APIError {
     super(
       `Timestamps are required in the collection ${collection.slug} because you have opted in to Versions.`,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'TimestampsRequired'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, TimestampsRequired.prototype)
   }
 }
diff --git a/packages/payload/src/errors/UnauthorizedError.ts b/packages/payload/src/errors/UnauthorizedError.ts
index 7baceb8167c..067f533bde1 100644
--- a/packages/payload/src/errors/UnauthorizedError.ts
+++ b/packages/payload/src/errors/UnauthorizedError.ts
@@ -8,5 +8,10 @@ import { APIError } from './APIError.js'
 export class UnauthorizedError extends APIError {
   constructor(t?: TFunction) {
     super(t ? t('error:unauthorized') : en.translations.error.unauthorized, httpStatus.UNAUTHORIZED)
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'UnauthorizedError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, UnauthorizedError.prototype)
   }
 }
diff --git a/packages/payload/src/errors/UnverifiedEmail.ts b/packages/payload/src/errors/UnverifiedEmail.ts
index 7a969d31e58..5e2dff40c23 100644
--- a/packages/payload/src/errors/UnverifiedEmail.ts
+++ b/packages/payload/src/errors/UnverifiedEmail.ts
@@ -11,5 +11,10 @@ export class UnverifiedEmail extends APIError {
       t ? t('error:unverifiedEmail') : en.translations.error.unverifiedEmail,
       httpStatus.FORBIDDEN,
     )
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'UnverifiedEmail'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, UnverifiedEmail.prototype)
   }
 }
diff --git a/packages/payload/src/errors/ValidationError.ts b/packages/payload/src/errors/ValidationError.ts
index 2dcca9b44a2..7cdbc975ed5 100644
--- a/packages/payload/src/errors/ValidationError.ts
+++ b/packages/payload/src/errors/ValidationError.ts
@@ -8,8 +8,10 @@ import type { PayloadRequest } from '../types/index.js'
 
 import { APIError } from './APIError.js'
 
-// This gets dynamically reassigned during compilation
-export let ValidationErrorName = 'ValidationError'
+/**
+ * @deprecated Remove this in 4.0 - this is no longer needed as we assign the prototype correctly in the constructor
+ */
+export const ValidationErrorName = 'ValidationError'
 
 export type ValidationFieldError = {
   label?: LabelFunction | StaticLabel
@@ -76,6 +78,9 @@ export class ValidationError extends APIError<{
       results,
     )
 
-    ValidationErrorName = this.constructor.name
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'ValidationError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, ValidationError.prototype)
   }
 }
diff --git a/packages/payload/src/queues/errors/index.ts b/packages/payload/src/queues/errors/index.ts
index 56b4b46ec5a..380bd89026c 100644
--- a/packages/payload/src/queues/errors/index.ts
+++ b/packages/payload/src/queues/errors/index.ts
@@ -28,6 +28,11 @@ export class TaskError extends Error {
   constructor(args: TaskErrorArgs) {
     super(args.message)
     this.args = args
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'TaskError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, TaskError.prototype)
   }
 }
 export class WorkflowError extends Error {
@@ -36,6 +41,11 @@ export class WorkflowError extends Error {
   constructor(args: WorkflowErrorArgs) {
     super(args.message)
     this.args = args
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'WorkflowError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, WorkflowError.prototype)
   }
 }
 
@@ -47,5 +57,10 @@ export class JobCancelledError extends Error {
   constructor(args: { job: Job }) {
     super(`Job ${args.job.id} was cancelled`)
     this.args = args
+
+    // Ensure error name is not lost during swc minification when running next build
+    this.name = 'JobCancelledError'
+    // Ensure instanceof works correctly
+    Object.setPrototypeOf(this, JobCancelledError.prototype)
   }
 }
diff --git a/packages/payload/src/utilities/formatErrors.ts b/packages/payload/src/utilities/formatErrors.ts
index 9011322d1ee..a81616ad655 100644
--- a/packages/payload/src/utilities/formatErrors.ts
+++ b/packages/payload/src/utilities/formatErrors.ts
@@ -1,20 +1,12 @@
 import type { ErrorResult } from '../config/types.js'
-import type { APIError } from '../errors/APIError.js'
 
-import { APIErrorName } from '../errors/APIError.js'
-import { ValidationErrorName } from '../errors/ValidationError.js'
+import { APIError } from '../errors/APIError.js'
+import { ValidationError } from '../errors/ValidationError.js'
 
-export const formatErrors = (incoming: { [key: string]: unknown } | APIError): ErrorResult => {
+export const formatErrors = (incoming: unknown): ErrorResult => {
   if (incoming) {
-    // Cannot use `instanceof` to check error type: https://github.com/microsoft/TypeScript/issues/13965
-    // Instead, get the prototype of the incoming error and check its constructor name
-    const proto = Object.getPrototypeOf(incoming)
-
     // Payload 'ValidationError' and 'APIError'
-    if (
-      (proto.constructor.name === ValidationErrorName || proto.constructor.name === APIErrorName) &&
-      incoming.data
-    ) {
+    if ((incoming instanceof ValidationError || incoming instanceof APIError) && incoming.data) {
       return {
         errors: [
           {
@@ -27,7 +19,13 @@ export const formatErrors = (incoming: { [key: string]: unknown } | APIError): E
     }
 
     // Mongoose 'ValidationError': https://mongoosejs.com/docs/api/error.html#Error.ValidationError
-    if (proto.constructor.name === ValidationErrorName && 'errors' in incoming && incoming.errors) {
+    if (
+      typeof incoming === 'object' &&
+      incoming !== null &&
+      !(incoming instanceof APIError || incoming instanceof Error) &&
+      'errors' in incoming &&
+      incoming.errors
+    ) {
       return {
         errors: Object.keys(incoming.errors).reduce(
           (acc, key) => {
@@ -42,17 +40,22 @@ export const formatErrors = (incoming: { [key: string]: unknown } | APIError): E
       }
     }
 
-    if (Array.isArray(incoming.message)) {
+    if (
+      typeof incoming === 'object' &&
+      incoming !== null &&
+      'message' in incoming &&
+      Array.isArray(incoming.message)
+    ) {
       return {
         errors: incoming.message,
       }
     }
 
-    if (incoming.name) {
+    if (typeof incoming === 'object' && incoming !== null && 'name' in incoming) {
       return {
         errors: [
           {
-            message: incoming.message,
+            message: (incoming as any).message,
           },
         ],
       }