diff --git a/src/node/ext/call.cc b/src/node/ext/call.cc
index c0e2b0f0e8fac71f8550eca326eec74721a4d21b..84a3e227c89344187b31bccf572f2052a31f9075 100644
--- a/src/node/ext/call.cc
+++ b/src/node/ext/call.cc
@@ -95,10 +95,6 @@ Local<Value> nanErrorWithCode(const char *msg, grpc_call_error code) {
   return scope.Escape(err);
 }
 
-bool EndsWith(const char *str, const char *substr) {
-  return strcmp(str+strlen(str)-strlen(substr), substr) == 0;
-}
-
 bool CreateMetadataArray(Local<Object> metadata, grpc_metadata_array *array,
                          shared_ptr<Resources> resources) {
   HandleScope scope;
@@ -126,7 +122,7 @@ bool CreateMetadataArray(Local<Object> metadata, grpc_metadata_array *array,
       grpc_metadata *current = &array->metadata[array->count];
       current->key = **utf8_key;
       // Only allow binary headers for "-bin" keys
-      if (EndsWith(current->key, "-bin")) {
+      if (grpc_is_binary_header(current->key, strlen(current->key))) {
         if (::node::Buffer::HasInstance(value)) {
           current->value = ::node::Buffer::Data(value);
           current->value_length = ::node::Buffer::Length(value);
@@ -180,7 +176,7 @@ Local<Value> ParseMetadata(const grpc_metadata_array *metadata_array) {
     } else {
       array = Local<Array>::Cast(maybe_array.ToLocalChecked());
     }
-    if (EndsWith(elem->key, "-bin")) {
+    if (grpc_is_binary_header(elem->key, strlen(elem->key))) {
       Nan::Set(array, index_map[elem->key],
                MakeFastBuffer(
                    Nan::CopyBuffer(elem->value,
diff --git a/src/node/ext/node_grpc.cc b/src/node/ext/node_grpc.cc
index 5b5f3c1c5b88321a79267ecf82450fa0ea34e852..a2b8e0d22bf12563cfe5c6428c1b54294a34b194 100644
--- a/src/node/ext/node_grpc.cc
+++ b/src/node/ext/node_grpc.cc
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -44,6 +44,7 @@
 #include "completion_queue_async_worker.h"
 #include "server_credentials.h"
 
+using v8::FunctionTemplate;
 using v8::Local;
 using v8::Value;
 using v8::Object;
@@ -230,6 +231,40 @@ void InitWriteFlags(Local<Object> exports) {
   Nan::Set(write_flags, Nan::New("NO_COMPRESS").ToLocalChecked(), NO_COMPRESS);
 }
 
+NAN_METHOD(MetadataKeyIsLegal) {
+  if (!info[0]->IsString()) {
+    return Nan::ThrowTypeError(
+        "headerKeyIsLegal's argument must be a string");
+  }
+  Local<String> key = Nan::To<String>(info[0]).ToLocalChecked();
+  char *key_str = *Nan::Utf8String(key);
+  info.GetReturnValue().Set(static_cast<bool>(
+      grpc_header_key_is_legal(key_str, static_cast<size_t>(key->Length()))));
+}
+
+NAN_METHOD(MetadataNonbinValueIsLegal) {
+  if (!info[0]->IsString()) {
+    return Nan::ThrowTypeError(
+        "metadataNonbinValueIsLegal's argument must be a string");
+  }
+  Local<String> value = Nan::To<String>(info[0]).ToLocalChecked();
+  char *value_str = *Nan::Utf8String(value);
+  info.GetReturnValue().Set(static_cast<bool>(
+      grpc_header_nonbin_value_is_legal(
+          value_str, static_cast<size_t>(value->Length()))));
+}
+
+NAN_METHOD(MetadataKeyIsBinary) {
+  if (!info[0]->IsString()) {
+    return Nan::ThrowTypeError(
+        "metadataKeyIsLegal's argument must be a string");
+  }
+  Local<String> key = Nan::To<String>(info[0]).ToLocalChecked();
+  char *key_str = *Nan::Utf8String(key);
+  info.GetReturnValue().Set(static_cast<bool>(
+      grpc_is_binary_header(key_str, static_cast<size_t>(key->Length()))));
+}
+
 void init(Local<Object> exports) {
   Nan::HandleScope scope;
   grpc_init();
@@ -247,6 +282,19 @@ void init(Local<Object> exports) {
   grpc::node::Server::Init(exports);
   grpc::node::CompletionQueueAsyncWorker::Init(exports);
   grpc::node::ServerCredentials::Init(exports);
+
+  // Attach a few utility functions directly to the module
+  Nan::Set(exports, Nan::New("metadataKeyIsLegal").ToLocalChecked(),
+           Nan::GetFunction(
+               Nan::New<FunctionTemplate>(MetadataKeyIsLegal)).ToLocalChecked());
+  Nan::Set(exports, Nan::New("metadataNonbinValueIsLegal").ToLocalChecked(),
+           Nan::GetFunction(
+               Nan::New<FunctionTemplate>(MetadataNonbinValueIsLegal)
+                            ).ToLocalChecked());
+  Nan::Set(exports, Nan::New("metadataKeyIsBinary").ToLocalChecked(),
+           Nan::GetFunction(
+               Nan::New<FunctionTemplate>(MetadataKeyIsBinary)
+                            ).ToLocalChecked());
 }
 
 NODE_MODULE(grpc_node, init)
diff --git a/src/node/src/metadata.js b/src/node/src/metadata.js
index 0a2f1489b6ead9db26642f983d69a2dec7083f6c..fef79f959e49323e6e5fad04f106324f21678c37 100644
--- a/src/node/src/metadata.js
+++ b/src/node/src/metadata.js
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -49,6 +49,8 @@
 
 var _ = require('lodash');
 
+var grpc = require('bindings')('grpc_node');
+
 /**
  * Class for storing metadata. Keys are normalized to lowercase ASCII.
  * @constructor
@@ -58,15 +60,16 @@ function Metadata() {
 }
 
 function normalizeKey(key) {
-  if (!(/^[A-Za-z\d_-]+$/.test(key))) {
-    throw new Error('Metadata keys must be nonempty strings containing only ' +
-        'alphanumeric characters and hyphens');
+  key = key.toLowerCase();
+  if (grpc.metadataKeyIsLegal(key)) {
+    return key;
+  } else {
+    throw new Error('Metadata key contains illegal characters');
   }
-  return key.toLowerCase();
 }
 
 function validate(key, value) {
-  if (_.endsWith(key, '-bin')) {
+  if (grpc.metadataKeyIsBinary(key)) {
     if (!(value instanceof Buffer)) {
       throw new Error('keys that end with \'-bin\' must have Buffer values');
     }
@@ -75,9 +78,8 @@ function validate(key, value) {
       throw new Error(
           'keys that don\'t end with \'-bin\' must have String values');
     }
-    if (!(/^[\x20-\x7E]*$/.test(value))) {
-      throw new Error('Metadata string values can only contain printable ' +
-          'ASCII characters and space');
+    if (!grpc.metadataNonbinValueIsLegal(value)) {
+      throw new Error('Metadata string value contains illegal characters');
     }
   }
 }