diff --git a/Makefile b/Makefile
index 61abfd4..a7ff5c1 100644
--- a/Makefile
+++ b/Makefile
@@ -15,8 +15,9 @@
 # <https://www.gnu.org/licenses/>.
 
 CFLAGS += -std=c11 -pedantic -Wall -Wextra
-CFLAGS += -O2 -flto
+CFLAGS += -O3 -flto
 CFLAGS += -D_XOPEN_SOURCE=700
+CFLAGS += -march=native
 
 SRC = main.c sud.c solve.c
 OBJ = $(SRC:.c=.o)