diff --git a/pythonlsf/Makefile b/pythonlsf/Makefile
index 7df6577..30c8e6a 100755
--- a/pythonlsf/Makefile
+++ b/pythonlsf/Makefile
@@ -13,7 +13,7 @@ LSF_INCLUDE = $(LSF_LIBDIR)/../../include/lsf/
 PROJECT = _lsf.so
 OBJECTS = lsf_wrap.o
 
-CFLAGS  = -m64 -fPIC -I$(PYTHON_INCLUDE) -I$(LSF_INCLUDE)
+CFLAGS  = -fPIC -I$(PYTHON_INCLUDE) -I$(LSF_INCLUDE)
 LDFLAGS = $(LSF_LIBDIR)/liblsf.a $(LSF_LIBDIR)/libbat.a $(LSF_LIBDIR)/libfairshareadjust.so $(LSF_LIBDIR)/liblsbstream.so -lc -lnsl -lz
 
 all: $(PROJECT)
diff --git a/setup.py b/setup.py
index 1476f9c..3e6d6bc 100755
--- a/setup.py
+++ b/setup.py
@@ -134,14 +134,13 @@ def set_gccflag_lsf_version():
                                        #   '-DLSF_SIMULATOR',
                                           '-DOS_HAS_THREAD -D_REENTRANT', 
                                             gccflag_keyvaluet, gccflag_lsfversion],
-                               extra_compile_args=['-m64', 
+                               extra_compile_args=[
                                     '-I' + LSF_LIBDIR + '/../../include/lsf/', 
                                     '-Wno-strict-prototypes', gccflag_keyvaluet,
                                     gccflag_lsfversion,
                                     '-DOS_HAS_THREAD -D_REENTRANT', #For multi-thread lib, lserrno
                                     '-Wp,-U_FORTIFY_SOURCE', #The flag needs -O option. Undefine it for warning.
                                     '-O0'], 
-                               extra_link_args=['-m64'],
                                extra_objects=lsf_static_lib,
                                libraries=lsf_dynamic_lib)],
       py_modules=['pythonlsf.lsf'],