diff --git a/index.js b/index.js
index a29e710..2a94fcb 100644
--- a/index.js
+++ b/index.js
@@ -109,6 +109,13 @@ function fastifyCompress (fastify, opts, next) {
 }
 
 const defaultCompressibleTypes = /^text\/(?!event-stream)|(?:\+|\/)json(?:;|$)|(?:\+|\/)text(?:;|$)|(?:\+|\/)xml(?:;|$)|octet-stream(?:;|$)/u
+const recommendedDefaultBrotliOptions = {
+  params: {
+    // Default of 4 as 11 has a heavy impact on performance.
+    // https://blog.cloudflare.com/this-is-brotli-from-origin#testing
+    [zlib.constants.BROTLI_PARAM_QUALITY]: 4
+  }
+}
 
 function processCompressParams (opts) {
   /* istanbul ignore next */
@@ -117,16 +124,13 @@ function processCompressParams (opts) {
   }
 
   const params = {
-    global: (typeof opts.global === 'boolean') ? opts.global : true,
-    /**
-     * Default of 4 as 11 has a heavy impact on performance.
-     * @see {@link https://blog.cloudflare.com/this-is-brotli-from-origin#testing}
-     */
-    brotliOptions: { [zlib.constants.BROTLI_PARAM_QUALITY]: 4, ...opts.brotliOptions }
+    global: (typeof opts.global === 'boolean') ? opts.global : true
   }
 
   params.removeContentLengthHeader = typeof opts.removeContentLengthHeader === 'boolean' ? opts.removeContentLengthHeader : true
-  params.brotliOptions = opts.brotliOptions
+  params.brotliOptions = params.global
+    ? { ...recommendedDefaultBrotliOptions, ...opts.brotliOptions }
+    : opts.brotliOptions
   params.zlibOptions = opts.zlibOptions
   params.onUnsupportedEncoding = opts.onUnsupportedEncoding
   params.inflateIfDeflated = opts.inflateIfDeflated === true
diff --git a/test/global-compress.test.js b/test/global-compress.test.js
index 659e2b4..a2c9595 100644
--- a/test/global-compress.test.js
+++ b/test/global-compress.test.js
@@ -2534,36 +2534,69 @@ test('When `encodings` option is set, it should only use the registered value',
   t.equal(response.statusCode, 200)
 })
 
-test('It should send data compressed according to `brotliOptions`', async (t) => {
-  t.plan(2)
-  const brotliOptions = {
-    params: {
-      [zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT,
-      [zlib.constants.BROTLI_PARAM_QUALITY]: 4
+test('It should send data compressed according to `brotliOptions` :', async (t) => {
+  t.test('when using br encoding', async (t) => {
+    t.plan(3)
+    const brotliOptions = {
+      params: {
+        [zlib.constants.BROTLI_PARAM_MODE]: zlib.constants.BROTLI_MODE_TEXT,
+        [zlib.constants.BROTLI_PARAM_QUALITY]: 8
+      }
     }
-  }
 
-  const fastify = Fastify()
-  await fastify.register(compressPlugin, { global: true, brotliOptions })
+    const fastify = Fastify()
+    await fastify.register(compressPlugin, { global: true, brotliOptions })
 
-  fastify.get('/', (request, reply) => {
-    reply
-      .type('text/plain')
-      .compress(createReadStream('./package.json'))
+    fastify.get('/', (request, reply) => {
+      reply
+        .type('text/plain')
+        .compress(createReadStream('./package.json'))
+    })
+
+    const response = await fastify.inject({
+      url: '/',
+      method: 'GET',
+      headers: {
+        'accept-encoding': 'br'
+      }
+    })
+
+    const file = readFileSync('./package.json', 'utf8')
+    const payload = zlib.brotliDecompressSync(response.rawPayload, brotliOptions)
+    t.equal(response.headers['content-encoding'], 'br')
+    t.equal(payload.toString('utf-8'), file)
+
+    const compressedPayload = zlib.brotliCompressSync(file, brotliOptions)
+    t.same(response.rawPayload, compressedPayload)
   })
 
-  const response = await fastify.inject({
-    url: '/',
-    method: 'GET',
-    headers: {
-      'accept-encoding': 'br'
+  t.test('default BROTLI_PARAM_QUALITY to be 4', async (t) => {
+    t.plan(1)
+
+    const fastify = Fastify()
+    await fastify.register(compressPlugin, { global: true })
+
+    const file = readFileSync('./package.json', 'utf8')
+    fastify.get('/', (request, reply) => {
+      reply
+        .type('text/plain')
+        .compress(file)
+    })
+
+    const response = await fastify.inject({
+      url: '/',
+      method: 'GET',
+      headers: {
+        'accept-encoding': 'br'
+      }
+    })
+
+    const defaultBrotliOptions = {
+      params: { [zlib.constants.BROTLI_PARAM_QUALITY]: 4 }
     }
+    const compressedPayload = zlib.brotliCompressSync(file, defaultBrotliOptions)
+    t.same(response.rawPayload, compressedPayload)
   })
-
-  const file = readFileSync('./package.json', 'utf8')
-  const payload = zlib.brotliDecompressSync(response.rawPayload, brotliOptions)
-  t.equal(response.headers['content-encoding'], 'br')
-  t.equal(payload.toString('utf-8'), file)
 })
 
 test('It should send data compressed according to `zlibOptions` :', async (t) => {
diff --git a/types/index.test-d.ts b/types/index.test-d.ts
index c102923..959709e 100644
--- a/types/index.test-d.ts
+++ b/types/index.test-d.ts
@@ -40,7 +40,7 @@ app.get('/test-two', async (request, reply) => {
   expectError(reply.compress())
 })
 
-// Instanciation of an app without global
+// Instantiation of an app without global
 const appWithoutGlobal: FastifyInstance = fastify()
 appWithoutGlobal.register(fastifyCompress, { global: false })
 
@@ -107,11 +107,11 @@ appWithoutGlobal.inject(
     }
   },
   (err) => {
-    expectType<Error>(err)
+    expectType<Error | undefined>(err)
   }
 )
 
-// Instanciation of an app that should trigger a typescript error
+// Instantiation of an app that should trigger a typescript error
 const appThatTriggerAnError = fastify()
 expectError(appThatTriggerAnError.register(fastifyCompress, {
   global: true,