diff --git a/src/hashing.ts b/src/hashing.ts
index 1256684..8298b95 100644
--- a/src/hashing.ts
+++ b/src/hashing.ts
@@ -1,14 +1,14 @@
 /* eslint-disable jsdoc/require-jsdoc */
 
-import { blake2b } from '@noble/hashes/blake2.js'
+import { blake512 } from '@noble/hashes/blake1.js'
 import type { Point } from '@zk-kit/baby-jubjub'
 import { leBigIntToBuffer, leBufferToBigInt } from '@zk-kit/utils'
 import { poseidon5 } from 'poseidon-lite'
 
 type HashFn = (m: Uint8Array) => Uint8Array
 // TODO: to modularize this hasher, we can add more hash functions here
-function blake2BWrapper (m: Uint8Array) {
-  return blake2b(m, { dkLen: 64 })
+function blake512Wrapper (m: Uint8Array) {
+  return blake512(m)
 }
 
 /**
@@ -29,7 +29,7 @@ class RFC9591Hasher {
    */
   constructor (contextString: string, order: bigint, hashFn?: HashFn) {
     this.contextString = contextString
-    this.hashFn = hashFn ?? blake2BWrapper
+    this.hashFn = hashFn ?? blake512Wrapper
     this.order = order
   }
 
diff --git a/test/hashes.test.ts b/test/hashes.test.ts
index 62e1382..5eb40b5 100644
--- a/test/hashes.test.ts
+++ b/test/hashes.test.ts
@@ -14,27 +14,27 @@ function toHex(buffer: Uint8Array) {
 const INPUT_HEX = '103056215bc7e90f9bbf1a4b4371b4484649a8ef98098c3326f9cb582673068a'
 const INPUT = hexToBytes(INPUT_HEX)
 
-// Expected vectors from the prompt
+// BLAKE-512 (BLAKE-1 / SHA-3 finalist) vectors for the 32-byte input above
 const VECTORS = {
   'H1': {
-    rawHex: '517822754585151647635ec2224ab27d6a83e6629ebf3d36b1ad419eb400b9e50352423edec008d7e08fe9fddc571f592ff82da660a02a2c3d5dbac8426a079d',
-    modDec: 1011714033864805916802867513617709433878078050615495686330311857274316592610n,
-    modHex: '0x23c9c1f2be6312c1cf47ab103220a6d50059f50020dbda92a158e5266eb15e2'
+    rawHex: 'db60748bfe364a66d8a534c9aae75ed21681ee98b2646e28a2348b851d4e1f0e6954f75d5146d5d99ae79f8a1c4a6af4ba056df0c4eee0032db0e67b42bf277b',
+    modDec: 1678949461854840229640339098254152788517688981803963206851042767735562726141n,
+    modHex: '0x3b64070b4bfe54a871407503712f1918062d4a26284774df303393d973c6afd'
   },
   'H3': {
-    rawHex: 'bcdd17d7d0d207a7fb860509ee09546dfca51454b0b591c547626e565272a1f60c0b37e46b18794793318ebd49c430349b2e467c0862d5bc9ebf4a868069f35f',
-    modDec: 2247655552097648134964227634858129138190003209803194921068384139971060600961n,
-    modHex: '0x4f820c1fc138c5e2dc3c7a16230acb75f8d13da98b23f952f561d3715489081'
+    rawHex: '5bbb9d21a860ca973b78cef0056a4c57c354ea0705e28136f447a736a75dd72b7f9e504a3f359a5840f3ace159ecc012d95a18f9ee94f0799462221675d22ff1',
+    modDec: 1213950929864348775292835996094940120861297402490820397600529732903868101565n,
+    modHex: '0x2af12668e8e162c9b3aa0ab3acea87d9542420ee5f0e5420671392dcd64f3bd'
   },
   'H4': {
-    rawHex: '39c1201c3014ba6032db564c77835ecc98a5e8f55ce10b904edba4293a00ad2fd792e0ed2b54e2621e7ed71c79e16a4e0d41e427f3240759b88e2a2f04df196e',
-    modDec: 2658467010355774823620755361084890962955677056727848814744952892684839397019n,
-    modHex: '0x5e0a395dcb3661341ee884396c6ce17c33f63a7c6ccf95e8849429da84ba69b'
+    rawHex: '2316e8d9a9db62b6c37b1d8d77a354b0335561c2a893ac5b2c7b08af4a5d978c761a64400ccf50bb9349baec2c29904da4e0dda54c564ff98cecb03da9bcb323',
+    modDec: 1252599766121406257733049228675028233963257259286401030830052074095697611857n,
+    modHex: '0x2c4f243918758686fd1a27d4572d6cb888aaadb0914a1ebac92f9c326064c51'
   },
   'H5': {
-    rawHex: '6146fffab891f131e3062a315b15f1973c549d98a56f9670c8912699aa5f177cca177e364308d02a298c15401f4bbe7f6ed0263be81b6597856f13ae89509d9a',
-    modDec: 1548104687198327700120789144102730872945653177570532681524096721970790712817n,
-    modHex: '0x36c323a46d1ebb644d126e0ae5f6ca61ad35252b8c7b8707fe6ae2df344c5f1'
+    rawHex: '53626e59d4f3f1aed62ead01bc0205e9c039b98fe1d30dabae22c37e8250e6a433d652c6c2958aa68bf7de931af787887a8d1c65fdb48cc10a3ffc53c760b9af',
+    modDec: 2053056783151336678290556986299662488575879129835563357194705989096511257949n,
+    modHex: '0x489fd2c7a4e21b7ae996096535f467ae251a13ab1cde88781ae06fe1ac23d5d'
   }
 } as const