diff --git a/test/private-box.test.ts b/test/private-box.test.ts
index 0b02a35..e00458e 100644
--- a/test/private-box.test.ts
+++ b/test/private-box.test.ts
@@ -1,5 +1,5 @@
 import {beforeAll, expect, test} from 'bun:test'
-import {PrivateBox} from '..'
+import {misc, PrivateBox} from '..'
 import {pubkey_toString} from '../src/misc'
 
 let k1!: CryptoKeyPair
@@ -9,7 +9,7 @@ let message!: Uint8Array
 beforeAll(async () => {
   k1 = await PrivateBox.gen(false)
   k2 = await PrivateBox.gen(true)
-  message = new TextEncoder().encode('Salut ! ça va ?')
+  message = misc.payload_fromString('Salut ! ça va ?')
 })
 
 test('base case', async () => {
@@ -35,12 +35,15 @@ test('Key generation', async () => {
 })
 
 test('serialization', async () => {
-  const message = new Uint8Array(8)
   const box = await PrivateBox.encrypt(message, k1.publicKey)
 
   const ser = await box.toString()
   const de = await PrivateBox.fromString(ser)
-  expect(de).not.toBeNull()
 
+  expect(de).not.toBeNull()
   expect(de).toEqual(box)
+
+  const unboxed = await de!.decrypt(k1.privateKey)
+  expect(unboxed).not.toBeNull()
+  expect(unboxed).toEqual(message)
 })
diff --git a/test/pwd-box.test.ts b/test/pwd-box.test.ts
index 5a51c9a..d1ae7cc 100644
--- a/test/pwd-box.test.ts
+++ b/test/pwd-box.test.ts
@@ -1,5 +1,5 @@
 import {beforeAll, expect, test} from 'bun:test'
-import {PwdBox} from '..'
+import {misc, PwdBox} from '..'
 
 let k1!: string
 let k2!: string
@@ -8,7 +8,7 @@ let message!: Uint8Array
 beforeAll(async () => {
   k1 = 'abc'
   k2 = 'def'
-  message = new TextEncoder().encode('Salut ! ça va ?')
+  message = misc.payload_fromString('Salut ! ça va ?')
 })
 
 test('base case', async () => {
@@ -23,12 +23,15 @@ test("Different key can't decrypt", async () => {
 })
 
 test('serialization', async () => {
-  const message = new Uint8Array(8)
   const box = await PwdBox.encrypt(message, k1)
 
   const ser = box.toString()
   const de = PwdBox.fromString(ser)
-  expect(de).not.toBeNull()
 
+  expect(de).not.toBeNull()
   expect(de).toEqual(box)
+
+  const unboxed = await de!.decrypt(k1)
+  expect(unboxed).not.toBeNull()
+  expect(unboxed).toEqual(message)
 })
diff --git a/test/secret-box.test.ts b/test/secret-box.test.ts
index 695b452..508f97d 100644
--- a/test/secret-box.test.ts
+++ b/test/secret-box.test.ts
@@ -1,5 +1,5 @@
 import {beforeAll, expect, test} from 'bun:test'
-import {SecretBox} from '..'
+import {SecretBox, misc} from '..'
 
 let k1!: CryptoKey
 let k2!: CryptoKey
@@ -8,7 +8,7 @@ let message!: Uint8Array
 beforeAll(async () => {
   k1 = await SecretBox.gen(false)
   k2 = await SecretBox.gen(true)
-  message = new TextEncoder().encode('Salut ! ça va ?')
+  message = misc.payload_fromString('Salut ! ça va ?')
 })
 
 test('base case', async () => {
@@ -28,12 +28,15 @@ test('Key generation', async () => {
 })
 
 test('serialization', async () => {
-  const message = new Uint8Array(8)
   const box = await SecretBox.encrypt(message, k1)
 
   const ser = box.toString()
   const de = SecretBox.fromString(ser)
-  expect(de).not.toBeNull()
 
+  expect(de).not.toBeNull()
   expect(de).toEqual(box)
+
+  const unboxed = await de!.decrypt(k1)
+  expect(unboxed).not.toBeNull()
+  expect(unboxed).toEqual(message)
 })