diff --git a/src/Makefile b/src/Makefile
index f9d1d7f..77310f4 100755
--- a/src/Makefile
+++ b/src/Makefile
@@ -12,4 +12,4 @@
 default: build
 
 build:
-	g++ -o chess.out functions.cpp chess.cpp -std=c++11
+	g++ -O2 -o chess.out functions.cpp chess.cpp -std=c++11