diff --git a/src/node_javascript.cc b/src/node_javascript.cc
index e8dc4ac4eaf2d2..d5377047c0ec5c 100644
--- a/src/node_javascript.cc
+++ b/src/node_javascript.cc
@@ -4,32 +4,30 @@
 #include "env.h"
 #include "env-inl.h"
 
-#include <string.h>
-#if !defined(_MSC_VER)
-#include <strings.h>
-#endif
-
 namespace node {
 
 using v8::HandleScope;
 using v8::Local;
+using v8::NewStringType;
 using v8::Object;
 using v8::String;
 
 Local<String> MainSource(Environment* env) {
-  return OneByteString(env->isolate(), node_native, sizeof(node_native) - 1);
+  return String::NewFromUtf8(
+      env->isolate(), reinterpret_cast<const char*>(node_native),
+      NewStringType::kNormal, sizeof(node_native)).ToLocalChecked();
 }
 
 void DefineJavaScript(Environment* env, Local<Object> target) {
   HandleScope scope(env->isolate());
 
-  for (int i = 0; natives[i].name; i++) {
-    if (natives[i].source != node_native) {
-      Local<String> name = String::NewFromUtf8(env->isolate(), natives[i].name);
-      Local<String> source = String::NewFromUtf8(env->isolate(),
-                                                  natives[i].source,
-                                                  String::kNormalString,
-                                                  natives[i].source_len);
+  for (auto native : natives) {
+    if (native.source != node_native) {
+      Local<String> name = String::NewFromUtf8(env->isolate(), native.name);
+      Local<String> source =
+          String::NewFromUtf8(
+              env->isolate(), reinterpret_cast<const char*>(native.source),
+              NewStringType::kNormal, native.source_len).ToLocalChecked();
       target->Set(name, source);
     }
   }
diff --git a/tools/js2c.py b/tools/js2c.py
index ec9705ec6af640..3e9a1c39cc496f 100755
--- a/tools/js2c.py
+++ b/tools/js2c.py
@@ -42,24 +42,7 @@
 
 
 def ToCArray(filename, lines):
-  result = []
-  row = 1
-  col = 0
-  for chr in lines:
-    col += 1
-    if chr == "\n" or chr == "\r":
-      row += 1
-      col = 0
-
-    value = ord(chr)
-
-    if value >= 128:
-      print 'non-ascii value ' + filename + ':' + str(row) + ':' + str(col)
-      sys.exit(1);
-
-    result.append(str(value))
-  result.append("0")
-  return ", ".join(result)
+  return ','.join(str(ord(c)) for c in lines)
 
 
 def CompressScript(lines, do_jsmin):
@@ -220,17 +203,11 @@ def ReadMacros(lines):
 
 struct _native {
   const char* name;
-  const char* source;
+  const unsigned char* source;
   size_t source_len;
 };
 
-static const struct _native natives[] = {
-
-%(native_lines)s\
-
-  { NULL, NULL, 0 } /* sentinel */
-
-};
+static const struct _native natives[] = { %(native_lines)s };
 
 }
 #endif
@@ -238,11 +215,11 @@ def ReadMacros(lines):
 
 
 NATIVE_DECLARATION = """\
-  { "%(id)s", %(escaped_id)s_native, sizeof(%(escaped_id)s_native)-1 },
+  { "%(id)s", %(escaped_id)s_native, sizeof(%(escaped_id)s_native) },
 """
 
 SOURCE_DECLARATION = """\
-  const char %(escaped_id)s_native[] = { %(data)s };
+  const unsigned char %(escaped_id)s_native[] = { %(data)s };
 """