--- SConstruct
+++ SConstruct
@@ -1,7 +1,21 @@
 import sys, os, shutil
+import SCons.Util
 
 env = Environment()
 
+if os.environ.has_key('CC'):
+   env['CC'] = os.environ['CC']
+if os.environ.has_key('CFLAGS'):
+   env['CCFLAGS'] += SCons.Util.CLVar(os.environ['CFLAGS'])
+if os.environ.has_key('CXX'):
+   env['CXX'] = os.environ['CXX']
+if os.environ.has_key('CXXFLAGS'):
+   env['CXXFLAGS'] += SCons.Util.CLVar(os.environ['CXXFLAGS'])
+if os.environ.has_key('LDFLAGS'):
+   env['LINKFLAGS'] += SCons.Util.CLVar(os.environ['LDFLAGS'])
+if "$CCFLAGS" in env['CXXCOM']:
+   env['CXXCOM'] = env['CXXCOM'].replace("$CCFLAGS","")
+
 opts = Variables()
 opts.Add(BoolVariable("mingwcross", "Cross-compile with mingw for Win32", 0))
 opts.Add(BoolVariable("boost_static", "Statically link against Boost", 0))
@@ -101,8 +115,7 @@
 sources = Glob('*.cpp') + ['cee/cee.cpp', 'bootloader/bootloader.cpp']
 
 json = env.Library('json', 
-	Glob('libjson/Source/*.cpp'),
-	CCFLAGS = "-c -O3 -ffast-math -fexpensive-optimizations".split()
+	Glob('libjson/Source/*.cpp')
 )
 
 websocketpp = env.Library('websocketpp', ['websocketpp/src/'+i for i in [
@@ -113,7 +126,7 @@
                 'websocket_session.cpp',
                 'sha1/sha1.cpp',
                 'base64/base64.cpp'
-            ]], CCFLAGS=['-g', '-O3'])
+            ]])
 
 
 libusb_cflags = []
@@ -127,14 +140,21 @@
 	libusb_os = ['os/poll_windows.c', 'os/windows_usb.c', 'os/threads_windows.c']
 	libusb_cflags += ['-D OS_WINDOWS', '-DPOLL_NFDS_TYPE=unsigned int', '-D WINVER=0x0501']
 
-libusb = env.Library('libusb_nonolith', ['libusb/libusb/'+i for i in [
+env_libusb = env.Clone()
+env_libusb.Append(CPPFLAGS=libusb_cflags)
+env_libusb.Append(CFLAGS=['-Ilibusb', '-Ilibusb/libusb'])
+
+libusb = env_libusb.Library('libusb_nonolith', ['libusb/libusb/'+i for i in [
 				'core.c',
 				'descriptor.c',
 				'io.c',
 				'sync.c',
-			]+libusb_os], CFLAGS=['-g', '-O3', '-Ilibusb', '-Ilibusb/libusb']+libusb_cflags) 
-
+			]+libusb_os])
 
 libs += boostlibs
 
-env.Program('nonolith-connect', sources, LIBS=libs, CCFLAGS=['-Wall', '-g', '-O3', '-Ilibusb', '-Iwebsocketpp/src', '-shared', "-DVERSION='%s'"%version], FRAMEWORKS=frameworks)
+env_main = env.Clone()
+env_main.Append(CPPFLAGS=["-DVERSION='%s'"%version])
+env_main.Append(CXXFLAGS=['-Ilibusb', '-Iwebsocketpp/src', '-Wall'])
+#env_main.Append(LINKFLAGS=['-shared'])
+env_main.Program('nonolith-connect', sources, LIBS=libs, FRAMEWORKS=frameworks)