diff --git a/bindings/python/ns3modulegen.py b/bindings/python/ns3modulegen.py
index e2e261b5b..1aa9c8c16 100755
--- a/bindings/python/ns3modulegen.py
+++ b/bindings/python/ns3modulegen.py
@@ -126,6 +126,15 @@ def main():
         except KeyError:
             pass
 
+    if 'Threading' not in enabled_features:
+        for clsname in ['SystemThread', 'SystemMutex', 'SystemCondition', 'CriticalSection']:
+            root_module.classes.remove(root_module['ns3::%s' % clsname])
+
+    if 'RealTime' not in enabled_features:
+        for clsname in ['WallClockSynchronizer', 'RealtimeSimulatorImpl', 'RealtimeEventLock']:
+            root_module.classes.remove(root_module['ns3::%s' % clsname])
+        root_module.enums.remove(root_module['ns3::RealtimeSimulatorImpl::SynchronizationMode'])
+
     root_module.generate(out, '_ns3')
 
     out.close()
diff --git a/src/core/wscript b/src/core/wscript
index 545a42e10..39b7846e9 100644
--- a/src/core/wscript
+++ b/src/core/wscript
@@ -28,6 +28,15 @@ def configure(conf):
     e.uselib = 'RT'
     e.run()
 
+    e = conf.create_header_configurator()
+    e.mandatory = False
+    e.name = 'pthread.h'
+    e.define = 'HAVE_PTHREAD_H'
+    conf.env['ENABLE_THREADING'] = e.run()
+    conf.report_optional_feature("Threading", "Threading Primitives",
+                                 conf.env['ENABLE_THREADING'],
+                                 "<pthread.h> include not detected")
+
     conf.write_config_header('ns3/core-config.h')
 
 def build(bld):
@@ -66,24 +75,9 @@ def build(bld):
         ]
     core.uselib = 'RT'
 
-    if sys.platform == 'win32':
-        core.source.extend([
-            'win32-system-wall-clock-ms.cc',
-            ])
-    else:
-        core.source.extend([
-            'unix-system-thread.cc',
-            'unix-system-mutex.cc',
-            'unix-system-condition.cc',
-            'unix-system-wall-clock-ms.cc',
-            ])
-    
     headers = bld.create_obj('ns3header')
     headers.module = 'core'
     headers.source = [
-        'system-mutex.h',
-        'system-thread.h',
-        'system-condition.h',
         'system-wall-clock-ms.h',
         'empty.h',
         'callback.h',
@@ -124,3 +118,24 @@ def build(bld):
         'deprecated.h'
         ]
 
+    if sys.platform == 'win32':
+        core.source.extend([
+            'win32-system-wall-clock-ms.cc',
+            ])
+    else:
+        core.source.extend([
+            'unix-system-wall-clock-ms.cc',
+            ])
+
+    if bld.env()['ENABLE_THREADING']:
+        core.source.extend([
+            'unix-system-thread.cc',
+            'unix-system-mutex.cc',
+            'unix-system-condition.cc',
+            ])
+        headers.source.extend([
+                'system-mutex.h',
+                'system-thread.h',
+                'system-condition.h',
+                ])
+
diff --git a/src/simulator/event-impl.h b/src/simulator/event-impl.h
index d0b0c13ae..36092fe9d 100644
--- a/src/simulator/event-impl.h
+++ b/src/simulator/event-impl.h
@@ -21,7 +21,6 @@
 #define EVENT_IMPL_H
 
 #include <stdint.h>
-#include "ns3/system-mutex.h"
 
 namespace ns3 {
 
diff --git a/src/simulator/wscript b/src/simulator/wscript
index a30e30bb3..90503fd2c 100644
--- a/src/simulator/wscript
+++ b/src/simulator/wscript
@@ -44,6 +44,9 @@ def configure(conf):
 
     conf.write_config_header('ns3/simulator-config.h')
 
+    conf.report_optional_feature("RealTime", "Real Time Simulator",
+                                 conf.env['ENABLE_THREADING'],
+                                 "threading not enabled")
 
 
 def build(bld):
@@ -59,11 +62,9 @@ def build(bld):
         'event-impl.cc',
         'simulator.cc',
         'default-simulator-impl.cc',
-        'realtime-simulator-impl.cc',
         'timer.cc',
         'watchdog.cc',
         'synchronizer.cc',
-        'wall-clock-synchronizer.cc',
         ]
 
     headers = bld.create_obj('ns3header')
@@ -76,7 +77,6 @@ def build(bld):
         'simulator.h',
         'simulator-impl.h',
         'default-simulator-impl.h',
-        'realtime-simulator-impl.h',
         'scheduler.h',
         'list-scheduler.h',
         'map-scheduler.h',
@@ -86,7 +86,6 @@ def build(bld):
         'timer-impl.h',
         'watchdog.h',
         'synchronizer.h',
-        'wall-clock-synchronizer.h',
         ]
 
     env = bld.env_of_name('default')
@@ -107,3 +106,13 @@ def build(bld):
             'cairo-wideint-private.h',
             ])
 
+    if env['ENABLE_THREADING']:
+        headers.source.extend([
+                'realtime-simulator-impl.h',
+                'wall-clock-synchronizer.h',
+                ])
+        sim.source.extend([
+                'realtime-simulator-impl.cc',
+                'wall-clock-synchronizer.cc',
+                ])
+