diff --git a/lib/adapters/http.js b/lib/adapters/http.js
index 10c24ce727..4965cd4859 100755
--- a/lib/adapters/http.js
+++ b/lib/adapters/http.js
@@ -20,6 +20,11 @@ import AxiosHeaders from '../core/AxiosHeaders.js';
 import AxiosTransformStream from '../helpers/AxiosTransformStream.js';
 import EventEmitter from 'events';
 
+const zlibOptions = {
+  flush: zlib.constants.Z_SYNC_FLUSH,
+  finishFlush: zlib.constants.Z_SYNC_FLUSH
+}
+
 const isBrotliSupported = utils.isFunction(zlib.createBrotliDecompress);
 
 const {http: httpFollow, https: httpsFollow} = followRedirects;
@@ -262,7 +267,7 @@ export default isHttpAdapterSupported && function httpAdapter(config) {
       }
     }
 
-    const contentLength = +headers.getContentLength();
+    const contentLength = utils.toFiniteNumber(headers.getContentLength());
 
     if (utils.isArray(maxRate)) {
       maxUploadRate = maxRate[0];
@@ -277,7 +282,7 @@ export default isHttpAdapterSupported && function httpAdapter(config) {
       }
 
       data = stream.pipeline([data, new AxiosTransformStream({
-        length: utils.toFiniteNumber(contentLength),
+        length: contentLength,
         maxRate: utils.toFiniteNumber(maxUploadRate)
       })], utils.noop);
 
@@ -320,7 +325,10 @@ export default isHttpAdapterSupported && function httpAdapter(config) {
       return reject(customErr);
     }
 
-    headers.set('Accept-Encoding', 'gzip, deflate, br', false);
+    headers.set(
+      'Accept-Encoding',
+      'gzip, compress, deflate' + (isBrotliSupported ? ', br' : ''), false
+      );
 
     const options = {
       path,
@@ -392,17 +400,17 @@ export default isHttpAdapterSupported && function httpAdapter(config) {
         streams.push(transformStream);
       }
 
-      // uncompress the response body transparently if required
+      // decompress the response body transparently if required
       let responseStream = res;
 
       // return the last request in case of redirects
       const lastRequest = res.req || req;
 
       // if decompress disabled we should not decompress
-      if (config.decompress !== false) {
+      if (config.decompress !== false && res.headers['content-encoding']) {
         // if no content, but headers still say that it is encoded,
         // remove the header not confuse downstream operations
-        if ((!responseLength || res.statusCode === 204) && res.headers['content-encoding']) {
+        if (method === 'HEAD' || res.statusCode === 204) {
           delete res.headers['content-encoding'];
         }
 
@@ -412,14 +420,14 @@ export default isHttpAdapterSupported && function httpAdapter(config) {
         case 'compress':
         case 'deflate':
           // add the unzipper to the body stream processing pipeline
-          streams.push(zlib.createUnzip());
+          streams.push(zlib.createUnzip(zlibOptions));
 
           // remove the content-encoding in order to not confuse downstream operations
           delete res.headers['content-encoding'];
           break;
         case 'br':
           if (isBrotliSupported) {
-            streams.push(zlib.createBrotliDecompress());
+            streams.push(zlib.createBrotliDecompress(zlibOptions));
             delete res.headers['content-encoding'];
           }
         }
diff --git a/test/unit/adapters/http.js b/test/unit/adapters/http.js
index 92a11a75e0..146cdda790 100644
--- a/test/unit/adapters/http.js
+++ b/test/unit/adapters/http.js
@@ -33,6 +33,7 @@ function setTimeoutAsync(ms) {
 
 const pipelineAsync = util.promisify(stream.pipeline);
 const finishedAsync = util.promisify(stream.finished);
+const gzip = util.promisify(zlib.gzip);
 
 function toleranceRange(positive, negative) {
   const p = (1 + 1 / positive);
@@ -497,6 +498,23 @@ describe('supports http with nodejs', function () {
 
       await axios.get(LOCAL_SERVER_URL);
     });
+
+    it('should not fail if response content-length header is missing', async () => {
+      this.timeout(10000);
+
+      const str = 'zipped';
+      const zipped = await gzip(str);
+
+      server = await startHTTPServer((req, res) => {
+        res.setHeader('Content-Encoding', 'gzip');
+        res.removeHeader('Content-Length');
+        res.end(zipped);
+      });
+
+      const {data} = await axios.get(LOCAL_SERVER_URL);
+
+      assert.strictEqual(data, str);
+    });
   });
 
   it('should support UTF8', function (done) {
@@ -1411,7 +1429,6 @@ describe('supports http with nodejs', function () {
 
   it('should omit a user-agent if one is explicitly disclaimed', function (done) {
     server = http.createServer(function (req, res) {
-      console.log(req.headers);
       assert.equal("user-agent" in req.headers, false);
       assert.equal("User-Agent" in req.headers, false);
       res.end();