diff --git a/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGServer.java b/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGServer.java
index c80c2f9f..a2934cbc 100644
--- a/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGServer.java
+++ b/nailgun-server/src/main/java/com/martiansoftware/nailgun/NGServer.java
@@ -347,7 +347,8 @@ public void shutdown(boolean exitVM) {
         System.setOut(out);
         System.setErr(err);
 
-        System.setSecurityManager(originalSecurityManager);
+        // Security manager is always disabled
+        //System.setSecurityManager(originalSecurityManager);
 
         if (exitVM) {
             System.exit(0);
@@ -381,10 +382,11 @@ public void run() {
         NGSession sessionOnDeck = null;
 
         originalSecurityManager = System.getSecurityManager();
-        System.setSecurityManager(
-                new NGSecurityManager(
-                originalSecurityManager));
 
+        // Remove overhead of security manager https://github.com/facebook/nailgun/issues/134
+        //System.setSecurityManager(
+        //        new NGSecurityManager(
+        //        originalSecurityManager));
 
         synchronized (System.in) {
             if (!(System.in instanceof ThreadLocalInputStream)) {