diff --git a/benchmark/run b/benchmark/run
index 3ba1a3e..d35bc6f 100755
--- a/benchmark/run
+++ b/benchmark/run
@@ -105,7 +105,7 @@ sys.puts("");
 
 Runner.run(benchmarks, runCount, {
   readFile: function(file) {
-    return fs.readFileSync(file, "utf-8");
+    return fs.readFileSync(file, "utf8");
   },
 
   testStart: function(benchmark, test) {
diff --git a/test/run b/test/run
index 02f562b..b81044a 100755
--- a/test/run
+++ b/test/run
@@ -81,7 +81,7 @@ QUnit.done = function(details) {
   "passes-test.js",
   "compiler-test.js",
 ].forEach(function(file) {
-  eval("with (QUnit) {" + fs.readFileSync(file, "utf-8") + "}");
+  eval("with (QUnit) {" + fs.readFileSync(file, "utf8") + "}");
 });
 
 QUnit.start();