diff --git a/src/cert/caas.js b/src/cert/caas.js
index b0c75c28e..6d867bce5 100644
--- a/src/cert/caas.js
+++ b/src/cert/caas.js
@@ -10,12 +10,12 @@ exports = module.exports = {
 var assert = require('assert'),
     debug = require('debug')('box:cert/caas.js');
 
-function getCertificate(domain, options, callback) {
-    assert.strictEqual(typeof domain, 'string');
+function getCertificate(vhost, options, callback) {
+    assert.strictEqual(typeof vhost, 'string');
     assert.strictEqual(typeof options, 'object');
     assert.strictEqual(typeof callback, 'function');
 
-    debug('getCertificate: using fallback certificate', domain);
+    debug('getCertificate: using fallback certificate', vhost);
 
-    return callback(null, 'cert/host.cert', 'cert/host.key');
+    return callback(null, '', '');
 }
diff --git a/src/cert/fallback.js b/src/cert/fallback.js
index fa645f68a..e74b75441 100644
--- a/src/cert/fallback.js
+++ b/src/cert/fallback.js
@@ -10,12 +10,12 @@ exports = module.exports = {
 var assert = require('assert'),
     debug = require('debug')('box:cert/fallback.js');
 
-function getCertificate(domain, options, callback) {
-    assert.strictEqual(typeof domain, 'string');
+function getCertificate(vhost, options, callback) {
+    assert.strictEqual(typeof vhost, 'string');
     assert.strictEqual(typeof options, 'object');
     assert.strictEqual(typeof callback, 'function');
 
-    debug('getCertificate: using fallback certificate', domain);
+    debug('getCertificate: using fallback certificate', vhost);
 
     return callback(null, '', '');
 }
diff --git a/src/reverseproxy.js b/src/reverseproxy.js
index 03468ca04..36cf4ca74 100644
--- a/src/reverseproxy.js
+++ b/src/reverseproxy.js
@@ -321,37 +321,37 @@ function ensureCertificate(app, callback) {
     assert.strictEqual(typeof app, 'object');
     assert.strictEqual(typeof callback, 'function');
 
-    var domain = app.altDomain || app.intrinsicFqdn;
+    var vhost = app.altDomain || app.intrinsicFqdn;
 
-    var certFilePath = path.join(paths.APP_CERTS_DIR, domain + '.user.cert');
-    var keyFilePath = path.join(paths.APP_CERTS_DIR, domain + '.user.key');
+    var certFilePath = path.join(paths.APP_CERTS_DIR, `${vhost}.user.cert`);
+    var keyFilePath = path.join(paths.APP_CERTS_DIR, `${vhost}.user.key`);
 
     if (fs.existsSync(certFilePath) && fs.existsSync(keyFilePath)) {
-        debug('ensureCertificate: %s. user certificate already exists at %s', domain, keyFilePath);
+        debug('ensureCertificate: %s. user certificate already exists at %s', vhost, keyFilePath);
         return callback(null, certFilePath, keyFilePath);
     }
 
-    certFilePath = path.join(paths.APP_CERTS_DIR, domain + '.cert');
-    keyFilePath = path.join(paths.APP_CERTS_DIR, domain + '.key');
+    certFilePath = path.join(paths.APP_CERTS_DIR, `${vhost}.cert`);
+    keyFilePath = path.join(paths.APP_CERTS_DIR, `${vhost}.key`);
 
     if (fs.existsSync(certFilePath) && fs.existsSync(keyFilePath)) {
-        debug('ensureCertificate: %s. certificate already exists at %s', domain, keyFilePath);
+        debug('ensureCertificate: %s. certificate already exists at %s', vhost, keyFilePath);
 
         if (!isExpiringSync(certFilePath, 24 * 1)) return callback(null, certFilePath, keyFilePath);
-        debug('ensureCertificate: %s cert require renewal', domain);
+        debug('ensureCertificate: %s cert require renewal', vhost);
     } else {
-        debug('ensureCertificate: %s cert does not exist', domain);
+        debug('ensureCertificate: %s cert does not exist', vhost);
     }
 
     getApi(app, function (error, api, apiOptions) {
         if (error) return callback(error);
 
-        debug('ensureCertificate: getting certificate for %s with options %j', domain, apiOptions);
+        debug('ensureCertificate: getting certificate for %s with options %j', vhost, apiOptions);
 
-        api.getCertificate(domain, apiOptions, function (error, certFilePath, keyFilePath) {
+        api.getCertificate(vhost, apiOptions, function (error, certFilePath, keyFilePath) {
             if (error) debug('ensureCertificate: could not get certificate. using fallback certs', error);
 
-            // if no cert was returned use fallback, the fallback provider will not provide any for example
+            // if no cert was returned use fallback. the fallback/caas provider will not provide any for example
             if (!certFilePath || !keyFilePath) {
                 certFilePath = path.join(paths.NGINX_CERT_DIR, `${app.domain}.host.cert`);
                 keyFilePath = path.join(paths.NGINX_CERT_DIR, `${app.domain}.host.key`);