diff --git a/SConstruct b/SConstruct

index bdafd06..9350c29 100644

--- a/SConstruct

+++ b/SConstruct

@@ -363,6 +363,11 @@ add_option('use-system-asio',

     nargs=0,

 )

+add_option('use-system-mozjs',

+    help="use system version of mozjs",

+    nargs=0,

+)

+

 add_option('use-system-intel_decimal128',

     help='use system version of intel decimal128',

     nargs=0,

@@ -2394,11 +2399,17 @@ def doConfigure(myenv):

     if use_system_version_of_library("intel_decimal128"):

         conf.FindSysLibDep("intel_decimal128", ["bid"])

+    if use_system_version_of_library("mozjs"):

+        conf.FindSysLibDep("mozjs", ["mozjs-38"])

+

     if wiredtiger and use_system_version_of_library("wiredtiger"):

         if not conf.CheckCXXHeader( "wiredtiger.h" ):

             myenv.ConfError("Cannot find wiredtiger headers")

         conf.FindSysLibDep("wiredtiger", ["wiredtiger"])

+    if use_system_version_of_library("asio"):

+        conf.CheckCXXHeader("asio.hpp")

+

     conf.env.Append(

         CPPDEFINES=[

             ("BOOST_THREAD_VERSION", "4"),

diff --git a/src/mongo/executor/connection_pool_asio.h b/src/mongo/executor/connection_pool_asio.h

index 2924331..54e5d53 100644

--- a/src/mongo/executor/connection_pool_asio.h

+++ b/src/mongo/executor/connection_pool_asio.h

@@ -35,6 +35,8 @@

 #include "mongo/executor/network_interface_asio.h"

 #include "mongo/stdx/mutex.h"

+#include <asio/steady_timer.hpp>

+

 namespace mongo {

 namespace executor {

 namespace connection_pool_asio {

diff --git a/src/third_party/SConscript b/src/third_party/SConscript

index 5ff1ace..dd3b73f 100644

--- a/src/third_party/SConscript

+++ b/src/third_party/SConscript

@@ -41,13 +41,18 @@ if not use_system_version_of_library('zlib'):

 # TODO: figure out if we want to offer system versions of mozjs.  Mozilla

 # hasn't offered a source tarball since 24, but in theory they could.

 #

-#if not use_system_version_of_library('mozjs'):

-if True:

+if not use_system_version_of_library('mozjs'):

     thirdPartyIncludePathList.append(

         ('mozjs', ['#/src/third_party/mozjs' + mozjsSuffix + '/include',

                    '#/src/third_party/mozjs' + mozjsSuffix + '/mongo_sources',

                    '#/src/third_party/mozjs' + mozjsSuffix + '/platform/' + env["TARGET_ARCH"] + "/" + env["TARGET_OS"] + "/include",

         ]))

+else:

+    thirdPartyIncludePathList.append(

+        ('mozjs', ['#/src/third_party/mozjs' + mozjsSuffix + '/mongo_sources', ]))

+    if use_system_version_of_library("mozjs"):

+        thirdPartyIncludePathList.append(

+            ('mozjs', ['/usr/include/mozjs' + mozjsSuffix, ]))

 if not use_system_version_of_library('stemmer'):

     thirdPartyIncludePathList.append(

@@ -198,13 +203,20 @@ zlibEnv.Library(

     ])

 if usemozjs:

-    mozjsEnv = env.Clone()

-    mozjsEnv.SConscript('mozjs' + mozjsSuffix + '/SConscript', exports={'env' : mozjsEnv })

-    mozjsEnv = mozjsEnv.Clone(

-        LIBDEPS=[

-            'mozjs' + mozjsSuffix + '/mozjs',

-            'shim_zlib',

-        ])

+    if use_system_version_of_library("mozjs"):

+        env.InjectThirdPartyIncludePaths(libraries=['mozjs'])

+        mozjsEnv = env.Clone(

+            SYSLIBDEPS=[

+                env['LIBDEPS_MOZJS_SYSLIBDEP'],

+            ])

+    else:

+        mozjsEnv = env.Clone()

+        mozjsEnv.SConscript('mozjs' + mozjsSuffix + '/SConscript', exports={'env' : mozjsEnv })

+        mozjsEnv = mozjsEnv.Clone(

+            LIBDEPS=[

+                'mozjs' + mozjsSuffix + '/mozjs',

+                'shim_zlib',

+            ])

     mozjsEnv.Library(

         target="shim_mozjs",

@@ -316,10 +328,7 @@ if wiredtiger:

         ])

 if use_system_version_of_library("asio"):

-    asioEnv = env.Clone(

-        SYSLIBDEPS=[

-            env['LIBDEPS_ASIO_SYSLIBDEP'],

-        ])

+    asioEnv = env.Clone()

 else:

     asioEnv = env.Clone()

     asioEnv.InjectThirdPartyIncludePaths(libraries=['asio'])