diff --git a/Makefile b/Makefile
index cf002f319..cfccec781 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ export CC  = gcc
 export CXX = g++
 export LDFLAGS= -pthread -lm 
 
-export CFLAGS = -Wall -O3 -msse2  -Wno-unknown-pragmas -fPIC 
+export CFLAGS = -Wall -O3 -msse2  -Wno-unknown-pragmas -fPIC -pedantic 
 
 ifeq ($(no_omp),1)
 	CFLAGS += -DDISABLE_OPENMP 
@@ -17,7 +17,7 @@ SLIB = wrapper/libxgboostwrapper.so
 
 .PHONY: clean all python 
 
-all: $(BIN) $(OBJ) $(SLIB)
+all: $(BIN) $(OBJ) $(SLIB) 
 
 python: wrapper/libxgboostwrapper.so
 # now the wrapper takes in two files. io and wrapper part
@@ -40,5 +40,17 @@ $(OBJ) :
 install:
 	cp -f -r $(BIN)  $(INSTALL_PATH)
 
+R-package.tar.gz:
+	rm -rf xgboost-R
+	cp -r R-package xgboost-R
+	rm -rf xgboost-R/src/*.o xgboost-R/src/*.so xgboost-R/src/*.dll
+	cp -r src xgboost-R/src/src
+	cp -r wrapper xgboost-R/src/wrapper
+	cp ./LICENSE xgboost-R
+	cat R-package/src/Makevars|sed '2s/.*/PKGROOT=./' > xgboost-R/src/Makevars
+	cat R-package/src/Makevars.win|sed '2s/.*/PKGROOT=./' > xgboost-R/src/Makevars.win
+	tar czf $@ xgboost-R
+	rm -rf xgboost-R
+
 clean:
 	$(RM) $(OBJ) $(BIN) $(SLIB) *.o *~ */*~ */*/*~
diff --git a/R-package/src/Makevars b/R-package/src/Makevars
index bfd52838f..1e77150db 100644
--- a/R-package/src/Makevars
+++ b/R-package/src/Makevars
@@ -1,12 +1,13 @@
+# package root
+PKGROOT=../../
 # _*_ mode: Makefile; _*_
 export CC  = gcc
 export CXX = g++
 
-# package root
-PKGROOT=../../
 
 # expose these flags to R CMD SHLIB
 PKG_CPPFLAGS = -O3 -Wno-unknown-pragmas  -DXGBOOST_CUSTOMIZE_ERROR_  -fPIC  $(SHLIB_OPENMP_CFLAGS)
+PKG_CPPFLAGS += -I$(PKGROOT)
 PKG_LIBS = $(SHLIB_OPENMP_CFLAGS)
 
 ifeq ($(no_omp),1)
diff --git a/R-package/src/Makevars.win b/R-package/src/Makevars.win
index 4cf21511a..c6d10bf1c 100644
--- a/R-package/src/Makevars.win
+++ b/R-package/src/Makevars.win
@@ -1,12 +1,13 @@
+# package root
+PKGROOT=../../
 # _*_ mode: Makefile; _*_
 export CC  = gcc
 export CXX = g++
 
-# package root
-PKGROOT=../../
 
 # expose these flags to R CMD SHLIB
 PKG_CPPFLAGS = -O3 -Wno-unknown-pragmas  -DXGBOOST_CUSTOMIZE_ERROR_ -fopenmp -fPIC  $(SHLIB_OPENMP_CFLAGS)
+PKG_CPPFLAGS += -I$(PKGROOT)
 PKG_LIBS = $(SHLIB_OPENMP_CFLAGS)
 
 # add flag to build native code even in cross compiler
diff --git a/R-package/src/xgboost_R.cpp b/R-package/src/xgboost_R.cpp
index a353041e0..b358ef4ae 100644
--- a/R-package/src/xgboost_R.cpp
+++ b/R-package/src/xgboost_R.cpp
@@ -3,10 +3,10 @@
 #include <utility>
 #include <cstring>
 #include "xgboost_R.h"
-#include "../../wrapper/xgboost_wrapper.h"
-#include "../../src/utils/utils.h"
-#include "../../src/utils/omp.h"
-#include "../../src/utils/matrix_csr.h"
+#include "wrapper/xgboost_wrapper.h"
+#include "src/utils/utils.h"
+#include "src/utils/omp.h"
+#include "src/utils/matrix_csr.h"
 
 using namespace xgboost;
 // implements error handling