diff --git a/test/parallel/test-zlib-params.js b/test/parallel/test-zlib-params.js
index 4e02b7bdb9461c..8a2b7da851225a 100644
--- a/test/parallel/test-zlib-params.js
+++ b/test/parallel/test-zlib-params.js
@@ -6,13 +6,13 @@ var path = require('path');
 var fs = require('fs');
 
 const file = fs.readFileSync(path.resolve(common.fixturesDir, 'person.jpg'));
-const chunkSize = 24 * 1024;
+const chunkSize = 12 * 1024;
 const opts = { level: 9, strategy: zlib.Z_DEFAULT_STRATEGY };
 const deflater = zlib.createDeflate(opts);
 
 const chunk1 = file.slice(0, chunkSize);
 const chunk2 = file.slice(chunkSize);
-const blkhdr = new Buffer([0x00, 0x48, 0x82, 0xb7, 0x7d]);
+const blkhdr = new Buffer([0x00, 0x5a, 0x82, 0xa5, 0x7d]);
 const expected = Buffer.concat([blkhdr, chunk2]);
 let actual;