diff --git a/Makefile b/Makefile
index b140c8a..d07789f 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,7 @@ DEBUG = stabs
 CSTANDARD = -std=gnu99
 
 # Place -D or -U options here
-CDEFS = -DF_CPU=16000000L -D__AVR__ -D__AVR_ATmega328P__
+CDEFS = -DF_CPU=1000000L -D__AVR__ -D__AVR_ATmega328P__
 
 # Place -I options here
 CINCS =