diff --git a/alexa-api/server.js b/alexa-api/server.js
index 636b147..d458e58 100644
--- a/alexa-api/server.js
+++ b/alexa-api/server.js
@@ -37,6 +37,7 @@ function httpsRequest(path, options, extraCookies) {
   extraCookies = extraCookies || '';
   return new Promise(function(resolve, reject) {
     var allCookies = ALEXA_COOKIE + (extraCookies ? '; ' + extraCookies : '');
+    var bodyBuf = options.body ? Buffer.from(options.body, 'utf8') : null;
     var reqOpts = {
       hostname: ALEXA_HOST,
       path: path,
@@ -46,7 +47,7 @@ function httpsRequest(path, options, extraCookies) {
         'Accept': 'application/json, text/plain, */*',
         'Accept-Language': 'ja-JP,ja;q=0.9',
         'Cookie': allCookies,
-      }, options.headers || {}),
+      }, bodyBuf ? { 'Content-Length': bodyBuf.length } : {}, options.headers || {}),
     };
     var req = https.request(reqOpts, function(res) {
       var body = '';
@@ -54,7 +55,7 @@ function httpsRequest(path, options, extraCookies) {
       res.on('end', function() { resolve({ status: res.statusCode, headers: res.headers, body: body }); });
     });
     req.on('error', reject);
-    if (options.body) req.write(options.body);
+    if (bodyBuf) req.write(bodyBuf);
     req.end();
   });
 }
@@ -136,8 +137,9 @@ app.post('/speak', async function(req, res) {
           deviceType: target.deviceType,
           deviceSerialNumber: target.serialNumber,
           customerId: customerId,
-          locale: '',
+          locale: 'ja-JP',
           textToSpeak: text,
+          speakType: 'ssml'
         },
       },
     };