diff --git a/test/parallel/test-benchmark-string_decoder.js b/test/parallel/test-benchmark-string_decoder.js
index a7329cc44f6339..a78390e03db87a 100644
--- a/test/parallel/test-benchmark-string_decoder.js
+++ b/test/parallel/test-benchmark-string_decoder.js
@@ -4,4 +4,7 @@ require('../common');
 
 const runBenchmark = require('../common/benchmark');
 
-runBenchmark('string_decoder', ['n=1']);
+runBenchmark('string_decoder', ['chunk=16',
+                                'encoding=utf8',
+                                'inlen=32',
+                                'n=1']);