diff --git a/Makefile b/Makefile
index 1819f38..7a31374 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 TARGET  = mgos_i2c
 CC      = gcc
 # CFLAGS  = -g -O -Wall -Wextra -std=c89 -pedantic -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition
-CFLAGS  = -g -O -Wall -Wextra -pedantic -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition
+CFLAGS  = -g -O2 -pedantic -Werror -Wall -Wextra -Wmissing-prototypes -Wstrict-prototypes -Wold-style-definition
 LINKER  = gcc
 LFLAGS  = -O -Wall -I. -lm