diff --git a/src/lib/check_key_type.ts b/src/lib/check_key_type.ts
index ae70854195..1c2f83339e 100644
--- a/src/lib/check_key_type.ts
+++ b/src/lib/check_key_type.ts
@@ -1,11 +1,11 @@
-import invalidKeyInput from './invalid_key_input.js'
+import { withAlg as invalidKeyInput } from './invalid_key_input.js'
 import isKeyLike, { types } from '../runtime/is_key_like.js'
 
-const symmetricTypeCheck = (key: unknown) => {
+const symmetricTypeCheck = (alg: string, key: unknown) => {
   if (key instanceof Uint8Array) return
 
   if (!isKeyLike(key)) {
-    throw new TypeError(invalidKeyInput(key, ...types, 'Uint8Array'))
+    throw new TypeError(invalidKeyInput(alg, key, ...types, 'Uint8Array'))
   }
 
   if (key.type !== 'secret') {
@@ -15,9 +15,9 @@ const symmetricTypeCheck = (key: unknown) => {
   }
 }
 
-const asymmetricTypeCheck = (key: unknown, usage: string) => {
+const asymmetricTypeCheck = (alg: string, key: unknown, usage: string) => {
   if (!isKeyLike(key)) {
-    throw new TypeError(invalidKeyInput(key, ...types))
+    throw new TypeError(invalidKeyInput(alg, key, ...types))
   }
 
   if (key.type === 'secret') {
@@ -65,9 +65,9 @@ const checkKeyType = (alg: string, key: unknown, usage: string): void => {
     /^A\d{3}(?:GCM)?KW$/.test(alg)
 
   if (symmetric) {
-    symmetricTypeCheck(key)
+    symmetricTypeCheck(alg, key)
   } else {
-    asymmetricTypeCheck(key, usage)
+    asymmetricTypeCheck(alg, key, usage)
   }
 }
 
diff --git a/src/lib/invalid_key_input.ts b/src/lib/invalid_key_input.ts
index dfcb74c9b8..2b99dd440c 100644
--- a/src/lib/invalid_key_input.ts
+++ b/src/lib/invalid_key_input.ts
@@ -1,6 +1,4 @@
-export default (actual: unknown, ...types: string[]) => {
-  let msg = 'Key must be '
-
+function message(msg: string, actual: unknown, ...types: string[]) {
   if (types.length > 2) {
     const last = types.pop()
     msg += `one of type ${types.join(', ')}, or ${last}.`
@@ -22,3 +20,11 @@ export default (actual: unknown, ...types: string[]) => {
 
   return msg
 }
+
+export default (actual: unknown, ...types: string[]) => {
+  return message('Key must be ', actual, ...types)
+}
+
+export function withAlg(alg: string, actual: unknown, ...types: string[]) {
+  return message(`Key for the ${alg} algorithm must be `, actual, ...types)
+}
diff --git a/test/unit/check_key_type.test.mjs b/test/unit/check_key_type.test.mjs
index 9975f6efda..1afe0c84df 100644
--- a/test/unit/check_key_type.test.mjs
+++ b/test/unit/check_key_type.test.mjs
@@ -17,7 +17,7 @@ const { generateKeyPair, generateSecret } = await import(keyRoot)
 test('lib/check_key_type.ts', async (t) => {
   const expected = {
     instanceOf: TypeError,
-    message: new RegExp(`^Key must be (?:one )?of type ${types}.`),
+    message: new RegExp(`^Key for the .+ algorithm must be (?:one )?of type ${types}\\.`),
   }
 
   t.throws(() => checkKeyType('HS256'), expected)
@@ -33,7 +33,7 @@ test('lib/check_key_type.ts', async (t) => {
 
   t.throws(() => checkKeyType('PS256', new Uint8Array()), {
     ...expected,
-    message: new RegExp(`^Key must be (?:one )?of type ${asymmetricTypes}\.`),
+    message: new RegExp(`^Key for the .+ algorithm must be (?:one )?of type ${asymmetricTypes}\\.`),
   })
   let secret = await generateSecret('HS256')
   t.throws(() => checkKeyType('PS256', secret), {