diff --git a/xs/src/libslic3r/PrintConfig.cpp b/xs/src/libslic3r/PrintConfig.cpp
index a93fcd00f0..1fc1bd5ce8 100644
--- a/xs/src/libslic3r/PrintConfig.cpp
+++ b/xs/src/libslic3r/PrintConfig.cpp
@@ -1,4 +1,5 @@
 #include "PrintConfig.hpp"
+#include <boost/thread.hpp>
 
 namespace Slic3r {
 
@@ -1247,7 +1248,7 @@ PrintConfigDef::PrintConfigDef()
     def->readonly = true;
     def->min = 1;
     def->max = 16;
-    def->default_value = new ConfigOptionInt(2);
+    def->default_value = new ConfigOptionInt(boost::thread::hardware_concurrency());
 
     def = this->add("toolchange_gcode", coString);
     def->label = "Tool change G-code";