diff --git a/Makefile b/Makefile
index 8fd04e3cd..b55cb3ac4 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 export CC  = gcc
 export CXX = g++
-export CFLAGS = -Wall -O3 -msse2  -Wno-unknown-pragmas
+export CFLAGS = -Wall -O3 -msse2  -Wno-unknown-pragmas -fopenmp
 
 # specify tensor path
 BIN = xgboost