diff --git a/SConstruct b/SConstruct
index f95b384eeb7..ef5b17bb8ad 100644
--- a/SConstruct
+++ b/SConstruct
@@ -215,7 +215,7 @@ nojni = not GetOption( "nojni" ) is None
 usesm = not GetOption( "usesm" ) is None
 usejvm = not GetOption( "usejvm" ) is None
 
-env = Environment( MSVS_ARCH=msarch )
+env = Environment( MSVS_ARCH=msarch , tools = ["default", "gch"], toolpath = '.' )
 if GetOption( "cxx" ) is not None:
     env["CC"] = GetOption( "cxx" )
     env["CXX"] = GetOption( "cxx" )
@@ -295,6 +295,8 @@ serverOnlyFiles += coreShardFiles + [ "s/d_logic.cpp" ]
 
 allClientFiles = commonFiles + coreDbFiles + [ "client/clientOnly.cpp" , "client/gridfs.cpp" ];
 
+allCXXFiles = allClientFiles + coreShardFiles + shardServerFiles + serverOnlyFiles;
+
 # ---- other build setup -----
 
 platform = os.sys.platform
@@ -511,7 +513,7 @@ if not nojni and useJavaHome:
     env.Append( LINKFLAGS="-Xlinker -rpath -Xlinker " + javaHome + "jre/lib/" + javaVersion  )
 
 if nix:
-    env.Append( CPPFLAGS="-fPIC -fno-strict-aliasing -ggdb -pthread -Wall -Wsign-compare -Wno-unknown-pragmas" )
+    env.Append( CPPFLAGS="-fPIC -fno-strict-aliasing -ggdb -pthread -Wall -Wsign-compare -Wno-unknown-pragmas -Winvalid-pch" )
     env.Append( CXXFLAGS=" -Wnon-virtual-dtor " )
     env.Append( LINKFLAGS=" -fPIC -pthread " )
     env.Append( LIBS=[] )
@@ -537,6 +539,14 @@ if nix:
     if GetOption( "profile" ) is not None:
         env.Append( LINKFLAGS=" -pg " )
 
+    # pre-compiled headers
+    if 'Gch' in dir( env ):
+        print( "using precompiled headers" )
+        env['Gch'] = env.Gch( [ "stdafx.h" ] )[0]
+        #Depends( "stdafx.o" , "stdafx.h.gch" )
+        #SideEffect( "dummyGCHSideEffect" , "stdafx.h.gch" )
+        
+
 if "uname" in dir(os):
     hacks = buildscripts.findHacks( os.uname() )
     if hacks is not None:
diff --git a/gch.py b/gch.py
new file mode 100644
index 00000000000..e5ff601638d
--- /dev/null
+++ b/gch.py
@@ -0,0 +1,108 @@
+# $Id$
+#
+# SCons builder for gcc's precompiled headers
+# Copyright (C) 2006  Tim Blechmann
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+# $Revision$
+# $LastChangedRevision$
+# $LastChangedDate$
+# $LastChangedBy$
+
+import SCons.Action
+import SCons.Builder
+import SCons.Scanner.C
+import SCons.Util
+import SCons.Script
+
+SCons.Script.EnsureSConsVersion(0,96,92)
+
+GchAction = SCons.Action.Action('$GCHCOM', '$GCHCOMSTR')
+GchShAction = SCons.Action.Action('$GCHSHCOM', '$GCHSHCOMSTR')
+
+def gen_suffix(env, sources):
+    return sources[0].get_suffix() + env['GCHSUFFIX']
+
+
+GchShBuilder = SCons.Builder.Builder(action = GchShAction,
+                                     source_scanner = SCons.Scanner.C.CScanner(),
+                                     suffix = gen_suffix)
+
+GchBuilder = SCons.Builder.Builder(action = GchAction,
+                                   source_scanner = SCons.Scanner.C.CScanner(),
+                                   suffix = gen_suffix)
+
+def static_pch_emitter(target,source,env):
+    SCons.Defaults.StaticObjectEmitter( target, source, env )
+
+    scanner = SCons.Scanner.C.CScanner()
+    path = scanner.path(env)
+    deps = scanner(source[0], env, path)
+
+    if env.has_key('Gch') and env['Gch']:
+        if env['Gch'].path.strip('.gch') in [x.path for x in deps]:
+            env.Depends(target, env['Gch'])
+
+    return (target, source)
+
+def shared_pch_emitter(target,source,env):
+    SCons.Defaults.SharedObjectEmitter( target, source, env )
+
+    scanner = SCons.Scanner.C.CScanner()
+    path = scanner.path(env)
+    deps = scanner(source[0], env, path)
+
+    if env.has_key('GchSh') and env['GchSh']:
+        if env['GchSh'].path.strip('.gch') in [x.path for x in deps]:
+            env.Depends(target, env['GchSh'])
+    return (target, source)
+
+def generate(env):
+    """
+    Add builders and construction variables for the Gch builder.
+    """
+    env.Append(BUILDERS = {
+        'gch': env.Builder(
+        action = GchAction,
+        target_factory = env.fs.File,
+        ),
+        'gchsh': env.Builder(
+        action = GchShAction,
+        target_factory = env.fs.File,
+        ),
+        })
+
+    try:
+        bld = env['BUILDERS']['Gch']
+        bldsh = env['BUILDERS']['GchSh']
+    except KeyError:
+        bld = GchBuilder
+        bldsh = GchShBuilder
+        env['BUILDERS']['Gch'] = bld
+        env['BUILDERS']['GchSh'] = bldsh
+
+    env['GCHCOM']     = '$CXX -o $TARGET -x c++-header -c $CXXFLAGS $_CCCOMCOM $SOURCE'
+    env['GCHSHCOM']   = '$CXX -o $TARGET -x c++-header -c $SHCXXFLAGS $_CCCOMCOM $SOURCE'
+    env['GCHSUFFIX']  = '.gch'
+
+    for suffix in SCons.Util.Split('.c .C .cc .cxx .cpp .c++'):
+        env['BUILDERS']['StaticObject'].add_emitter( suffix, static_pch_emitter )
+        env['BUILDERS']['SharedObject'].add_emitter( suffix, shared_pch_emitter )
+
+
+def exists(env):
+    return env.Detect('g++')