diff --git a/Makefile b/Makefile
index 2fe845e..2778911 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 PREFIX=
 CC=cc
-CFLAGS=-O3
-LIBS=-lncurses
+CFLAGS=-O3 -std=gnu99
+LIBS=-lncurses -lm
 
 all: ascii