diff --git a/Makefile b/Makefile
index e1b93d814..a41724291 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 export CC  = gcc
 export CXX = g++
 export MPICXX = mpicxx
-export LDFLAGS= -Lrabit/lib -pthread -lm 
+export LDFLAGS= -pthread -lm 
 export CFLAGS = -Wall -O3 -msse2  -Wno-unknown-pragmas -fPIC
 
 ifeq ($(no_omp),1)
@@ -11,9 +11,9 @@ else
 endif
 
 # by default use c++11
-ifeq ($(no_cxx11),1)
+ifeq ($(cxx11),1)
+	CFLAGS += -std=c++11
 else 
-	CFLAGS += 
 endif
 
 # specify tensor path
@@ -72,15 +72,18 @@ install:
 
 Rpack:
 	make clean
+	cd subtree/rabit;make clean;cd -
 	rm -rf xgboost xgboost*.tar.gz
 	cp -r R-package xgboost
 	rm -rf xgboost/inst/examples/*.buffer
 	rm -rf xgboost/inst/examples/*.model
 	rm -rf xgboost/inst/examples/dump*
 	rm -rf xgboost/src/*.o xgboost/src/*.so xgboost/src/*.dll
+	rm -rf xgboost/subtree/rabit/src/*.o
 	rm -rf xgboost/demo/*.model xgboost/demo/*.buffer xgboost/demo/*.txt
 	rm -rf xgboost/demo/runall.R
 	cp -r src xgboost/src/src
+	cp -r subtree xgboost/src/subtree
 	mkdir xgboost/src/wrapper
 	cp  wrapper/xgboost_wrapper.h xgboost/src/wrapper
 	cp  wrapper/xgboost_wrapper.cpp xgboost/src/wrapper
diff --git a/R-package/src/Makevars b/R-package/src/Makevars
index 5cea1438c..cc933f099 100644
--- a/R-package/src/Makevars
+++ b/R-package/src/Makevars
@@ -1,7 +1,7 @@
 # package root
 PKGROOT=../../
 # _*_ mode: Makefile; _*_
-PKG_CPPFLAGS= -DXGBOOST_CUSTOMIZE_MSG_ -DXGBOOST_CUSTOMIZE_PRNG_ -DXGBOOST_STRICT_CXX98_ -I$(PKGROOT)
+PKG_CPPFLAGS= -DXGBOOST_CUSTOMIZE_MSG_ -DXGBOOST_CUSTOMIZE_PRNG_ -DXGBOOST_STRICT_CXX98_ -DRABIT_CUSTOMIZE_MSG_ -DRABIT_STRICT_CXX98_ -I$(PKGROOT)
 PKG_CXXFLAGS= $(SHLIB_OPENMP_CFLAGS)
 PKG_LIBS = $(SHLIB_OPENMP_CFLAGS)
-OBJECTS= xgboost_R.o xgboost_assert.o $(PKGROOT)/wrapper/xgboost_wrapper.o $(PKGROOT)/src/io/io.o $(PKGROOT)/src/gbm/gbm.o $(PKGROOT)/src/tree/updater.o $(PKGROOT)/src/sync/sync_empty.o
+OBJECTS= xgboost_R.o xgboost_assert.o $(PKGROOT)/wrapper/xgboost_wrapper.o $(PKGROOT)/src/io/io.o $(PKGROOT)/src/gbm/gbm.o $(PKGROOT)/src/tree/updater.o $(PKGROOT)/subtree/rabit/src/engine_empty.o
diff --git a/R-package/src/Makevars.win b/R-package/src/Makevars.win
index 5cea1438c..0ae038561 100644
--- a/R-package/src/Makevars.win
+++ b/R-package/src/Makevars.win
@@ -1,7 +1,7 @@
 # package root
 PKGROOT=../../
 # _*_ mode: Makefile; _*_
-PKG_CPPFLAGS= -DXGBOOST_CUSTOMIZE_MSG_ -DXGBOOST_CUSTOMIZE_PRNG_ -DXGBOOST_STRICT_CXX98_ -I$(PKGROOT)
+PKG_CPPFLAGS= -DXGBOOST_CUSTOMIZE_MSG_ -DXGBOOST_CUSTOMIZE_PRNG_ -DXGBOOST_STRICT_CXX98_ -DRABIT_CUSTOMIZE_MSG_ -DRABIT_STRICT_CXX98_ -I$(PKGROOT)
 PKG_CXXFLAGS= $(SHLIB_OPENMP_CFLAGS)
 PKG_LIBS = $(SHLIB_OPENMP_CFLAGS)
 OBJECTS= xgboost_R.o xgboost_assert.o $(PKGROOT)/wrapper/xgboost_wrapper.o $(PKGROOT)/src/io/io.o $(PKGROOT)/src/gbm/gbm.o $(PKGROOT)/src/tree/updater.o $(PKGROOT)/src/sync/sync_empty.o
diff --git a/README.md b/README.md
index 6bc92ed04..6c7a538e7 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,8 @@ Features
 Build
 =====
 * Run ```bash build.sh``` (you can also type make)
+* If you have C++11 compiler, it is recommended to type ```make cxx11=1```
+  - C++11 is not used by default
 * If your compiler does not come with OpenMP support, it will fire an warning telling you that the code will compile into single thread mode, and you will get single thread xgboost
 * You may get a error: -lgomp is not found
   - You can type ```make no_omp=1```, this will get you single thread xgboost
diff --git a/build.sh b/build.sh
index f6fbcb74b..055e75c33 100755
--- a/build.sh
+++ b/build.sh
@@ -5,11 +5,7 @@
 # In most cases, type make will give what you want
 
 # download rabit
-if [ ! -d rabit ]; then
-    git clone https://github.com/tqchen/rabit.git
-else
-    cd rabit; git pull; cd ..
-fi
+
 if make; then
     echo "Successfully build multi-thread xgboost"
 else