diff --git a/__tests__/config.test.ts b/__tests__/config.test.ts
index 315a752..3f26da1 100644
--- a/__tests__/config.test.ts
+++ b/__tests__/config.test.ts
@@ -1,13 +1,9 @@
 import {expect, test, beforeEach} from '@jest/globals'
 import {readConfig} from '../src/config'
 import {getRefs} from '../src/git-refs'
-import * as Utils from '../src/utils'
+import * as spdx from '../src/spdx'
 import {setInput, clearInputs} from './test-helpers'
 
-beforeAll(() => {
-  jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(true)
-})
-
 beforeEach(() => {
   clearInputs()
 })
@@ -19,11 +15,11 @@ test('it defaults to low severity', async () => {
 
 test('it reads custom configs', async () => {
   setInput('fail-on-severity', 'critical')
-  setInput('allow-licenses', ' BSD, GPL 2')
+  setInput('allow-licenses', 'ISC, GPL-2.0')
 
   const config = await readConfig()
   expect(config.fail_on_severity).toEqual('critical')
-  expect(config.allow_licenses).toEqual(['BSD', 'GPL 2'])
+  expect(config.allow_licenses).toEqual(['ISC', 'GPL-2.0'])
 })
 
 test('it defaults to false for warn-only', async () => {
@@ -40,7 +36,7 @@ test('it defaults to empty allow/deny lists ', async () => {
 
 test('it raises an error if both an allow and denylist are specified', async () => {
   setInput('allow-licenses', 'MIT')
-  setInput('deny-licenses', 'BSD')
+  setInput('deny-licenses', 'BSD-3-Clause')
 
   await expect(readConfig()).rejects.toThrow(
     'You cannot specify both allow-licenses and deny-licenses'
@@ -204,21 +200,17 @@ test('it is not possible to disable both checks', async () => {
 })
 
 describe('licenses that are not valid SPDX licenses', () => {
-  beforeAll(() => {
-    jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(false)
-  })
-
   test('it raises an error for invalid licenses in allow-licenses', async () => {
-    setInput('allow-licenses', ' BSD, GPL 2')
+    setInput('allow-licenses', ' BSD-YOLO, GPL-2.0')
     await expect(readConfig()).rejects.toThrow(
-      'Invalid license(s) in allow-licenses: BSD,GPL 2'
+      'Invalid license(s) in allow-licenses: BSD-YOLO'
     )
   })
 
   test('it raises an error for invalid licenses in deny-licenses', async () => {
-    setInput('deny-licenses', ' BSD, GPL 2')
+    setInput('deny-licenses', ' GPL-2.0, BSD-YOLO, Apache-2.0, ToIll')
     await expect(readConfig()).rejects.toThrow(
-      'Invalid license(s) in deny-licenses: BSD,GPL 2'
+      'Invalid license(s) in deny-licenses: BSD-YOLO, ToIll'
     )
   })
 })
diff --git a/__tests__/deny.test.ts b/__tests__/deny.test.ts
index 24e6be8..ad4fec6 100644
--- a/__tests__/deny.test.ts
+++ b/__tests__/deny.test.ts
@@ -33,11 +33,6 @@ jest.mock('octokit', () => {
 
 beforeEach(async () => {
   jest.resetModules()
-  jest.doMock('spdx-satisfies', () => {
-    // mock spdx-satisfies return value
-    // true for BSD, false for all others
-    return jest.fn((license: string, _: string): boolean => license === 'BSD')
-  })
 
   npmChange = createTestChange({ecosystem: 'npm'})
   rubyChange = createTestChange({ecosystem: 'rubygems'})
diff --git a/__tests__/external-config.test.ts b/__tests__/external-config.test.ts
index a1a0e7c..e525b71 100644
--- a/__tests__/external-config.test.ts
+++ b/__tests__/external-config.test.ts
@@ -1,6 +1,6 @@
 import {expect, test, beforeEach} from '@jest/globals'
 import {readConfig} from '../src/config'
-import * as Utils from '../src/utils'
+import * as spdx from '../src/spdx'
 import {setInput, clearInputs} from './test-helpers'
 
 const externalConfig = `fail_on_severity: 'high'
@@ -25,10 +25,6 @@ jest.mock('octokit', () => {
   }
 })
 
-beforeAll(() => {
-  jest.spyOn(Utils, 'isSPDXValid').mockReturnValue(true)
-})
-
 beforeEach(() => {
   clearInputs()
 })
diff --git a/__tests__/spdx.test.ts b/__tests__/spdx.test.ts
index 460f4f1..95eb50c 100644
--- a/__tests__/spdx.test.ts
+++ b/__tests__/spdx.test.ts
@@ -1,7 +1,7 @@
 import {expect, jest, test} from '@jest/globals'
 import * as spdx from '../src/spdx'
 
-test('hello', () => {
+test('satisfies', () => {
   expect(spdx.satisfies('MIT', 'MIT')).toBe(true)
 })
 
diff --git a/src/config.ts b/src/config.ts
index 2a14a48..b2198ff 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -5,7 +5,7 @@ import * as core from '@actions/core'
 import * as z from 'zod'
 import {ConfigurationOptions, ConfigurationOptionsSchema} from './schemas'
 import {octokitClient} from './utils'
-import {isValidSPDX} from './spdx'
+import {isValid} from './spdx'
 
 type ConfigurationOptionsPartial = Partial<ConfigurationOptions>
 
@@ -114,10 +114,12 @@ function validateLicenses(
     return
   }
 
-  const invalid_licenses = licenses.filter(license => !isValidSPDX(license))
+  const invalid_licenses = licenses.filter(license => !isValid(license))
 
   if (invalid_licenses.length > 0) {
-    throw new Error(`Invalid license(s) in ${key}: ${invalid_licenses}`)
+    throw new Error(
+      `Invalid license(s) in ${key}: ${invalid_licenses.join(', ')}`
+    )
   }
 }
 
diff --git a/src/licenses.ts b/src/licenses.ts
index 76008bc..8c88899 100644
--- a/src/licenses.ts
+++ b/src/licenses.ts
@@ -2,7 +2,7 @@ import spdxSatisfies from 'spdx-satisfies'
 import {Change, Changes} from './schemas'
 import {octokitClient} from './utils'
 import {parsePURL} from './purl'
-import {isValidSPDX} from './spdx'
+import {isValid} from './spdx'
 
 /**
  * Loops through a list of changes, filtering and returning the
@@ -166,7 +166,7 @@ const setGHLicenses = async (changes: Change[]): Promise<Change[]> => {
 // Currently Dependency Graph licenses are truncated to 255 characters
 // This possibly makes them invalid spdx ids
 const truncatedDGLicense = (license: string): boolean =>
-  license.length === 255 && !isValidSPDX(license)
+  license.length === 255 && !isValid(license)
 
 async function groupChanges(
   changes: Changes
diff --git a/src/spdx.ts b/src/spdx.ts
index 85c1f89..0ba6d7f 100644
--- a/src/spdx.ts
+++ b/src/spdx.ts
@@ -9,7 +9,7 @@ export function satisfies(
 }
 
 // can be a single license or an SPDX expression
-export function isValidSPDX(spdxExpr: string): boolean {
+export function isValid(spdxExpr: string): boolean {
   try {
     parse(spdxExpr)
     return true