diff --git a/src/config.js b/src/config.js
index 6142c1955..4caa0b933 100644
--- a/src/config.js
+++ b/src/config.js
@@ -29,7 +29,6 @@ exports = module.exports = {
     sysadminOrigin: sysadminOrigin, // localhost routes
     adminFqdn: adminFqdn,
     mailFqdn: mailFqdn,
-    hasIPv6: hasIPv6,
 
     isDemo: isDemo,
 
@@ -195,9 +194,3 @@ function isDemo() {
 function provider() {
     return get('provider');
 }
-
-function hasIPv6() {
-    const IPV6_PROC_FILE = '/proc/net/if_inet6';
-    // on contabo, /proc/net/if_inet6 is an empty file. so just exists is not enough
-    return fs.existsSync(IPV6_PROC_FILE) && fs.readFileSync(IPV6_PROC_FILE, 'utf8').trim().length !== 0;
-}
diff --git a/src/reverseproxy.js b/src/reverseproxy.js
index ad58b0980..d5a7392ea 100644
--- a/src/reverseproxy.js
+++ b/src/reverseproxy.js
@@ -52,6 +52,7 @@ var acme2 = require('./cert/acme2.js'),
     rimraf = require('rimraf'),
     safe = require('safetydance'),
     shell = require('./shell.js'),
+    sysinfo = require('./sysinfo.js'),
     users = require('./users.js'),
     util = require('util');
 
@@ -388,7 +389,7 @@ function writeAdminNginxConfig(bundle, configFileName, vhost, callback) {
         sourceDir: path.resolve(__dirname, '..'),
         adminOrigin: config.adminOrigin(),
         vhost: vhost, // if vhost is empty it will become the default_server
-        hasIPv6: config.hasIPv6(),
+        hasIPv6: sysinfo.hasIPv6(),
         endpoint: 'admin',
         certFilePath: bundle.certFilePath,
         keyFilePath: bundle.keyFilePath,
@@ -451,7 +452,7 @@ function writeAppNginxConfig(app, bundle, callback) {
         sourceDir: sourceDir,
         adminOrigin: config.adminOrigin(),
         vhost: app.fqdn,
-        hasIPv6: config.hasIPv6(),
+        hasIPv6: sysinfo.hasIPv6(),
         port: app.httpPort,
         endpoint: endpoint,
         certFilePath: bundle.certFilePath,
@@ -481,7 +482,7 @@ function writeAppRedirectNginxConfig(app, fqdn, bundle, callback) {
         sourceDir: path.resolve(__dirname, '..'),
         vhost: fqdn,
         redirectTo: app.fqdn,
-        hasIPv6: config.hasIPv6(),
+        hasIPv6: sysinfo.hasIPv6(),
         endpoint: 'redirect',
         certFilePath: bundle.certFilePath,
         keyFilePath: bundle.keyFilePath,
diff --git a/src/sysinfo.js b/src/sysinfo.js
index 323b7193d..9942d2368 100644
--- a/src/sysinfo.js
+++ b/src/sysinfo.js
@@ -3,12 +3,15 @@
 exports = module.exports = {
     SysInfoError: SysInfoError,
 
-    getPublicIp: getPublicIp
+    getPublicIp: getPublicIp,
+
+    hasIPv6: hasIPv6
 };
 
 var assert = require('assert'),
     config = require('./config.js'),
     ec2 = require('./sysinfo/ec2.js'),
+    fs = require('fs'),
     generic = require('./sysinfo/generic.js'),
     scaleway = require('./sysinfo/scaleway.js'),
     util = require('util');
@@ -56,3 +59,9 @@ function getPublicIp(callback) {
         api.getPublicIp(callback);
     });
 }
+
+function hasIPv6() {
+    const IPV6_PROC_FILE = '/proc/net/if_inet6';
+    // on contabo, /proc/net/if_inet6 is an empty file. so just exists is not enough
+    return fs.existsSync(IPV6_PROC_FILE) && fs.readFileSync(IPV6_PROC_FILE, 'utf8').trim().length !== 0;
+}
diff --git a/src/test/config-test.js b/src/test/config-test.js
index 369bb62ce..67e1528e5 100644
--- a/src/test/config-test.js
+++ b/src/test/config-test.js
@@ -79,8 +79,4 @@ describe('config', function () {
 
         done();
     });
-
-    it('test machine has IPv6 support', function () {
-        expect(config.hasIPv6()).to.equal(true);
-    });
 });
diff --git a/src/test/sysinfo-test.js b/src/test/sysinfo-test.js
new file mode 100644
index 000000000..beee4a307
--- /dev/null
+++ b/src/test/sysinfo-test.js
@@ -0,0 +1,24 @@
+/* global it:false */
+/* global describe:false */
+/* global after:false */
+/* global before:false */
+
+'use strict';
+
+var config = require('../config.js'),
+    expect = require('expect.js'),
+    sysinfo = require('../sysinfo.js');
+
+describe('config', function () {
+    before(function () {
+        config._reset();
+    });
+
+    after(function () {
+        config._reset();
+    });
+
+    it('test machine has IPv6 support', function () {
+        expect(sysinfo.hasIPv6()).to.equal(true);
+    });
+});