diff --git a/Makefile b/Makefile
index aaa7d2e..0445bdd 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ TARGET = $(BUILDFOLDER)$(TARGETNAME)
 
 INC = -Isrc/include -I/usr/avr/include
 CFLAGS = -Wall -Wpedantic -Wextra -Os -mmcu=atmega32u4
-CPPFLAGS = -DF_CPU=8000000UL
+CPPFLAGS = -DF_CPU=16000000UL
 
 SRC = $(wildcard src/*.c)