diff --git a/01_git/Makefile.UNIX b/01_git/Makefile.UNIX
index 00f608a79ef8c17eebc2509c7d5c7ac0e7ad8a12..72a051909afea6513bf70b9af163173d68e27b7e 100644
--- a/01_git/Makefile.UNIX
+++ b/01_git/Makefile.UNIX
@@ -12,7 +12,7 @@ C_INCLUDE = -I. -I/usr/X11R6/include
 
 #-----------------------------------------------------
 CC = gcc
-COPTS = -O3 -std=c99 -pipe -Wall -D_BSD_SOURCE -D_XOPEN_SOURCE=600 -pedantic -Werror -pedantic-errors
+COPTS = -O3 -std=c99 -pipe -Wall -DNDEBUG -D_BSD_SOURCE -D_XOPEN_SOURCE=600 -Werror -pedantic-errors
 #COMPILE_FLAGS = -DDEBUG -DTEST -g
 
 CFLAGS = $(COPTS) $(COMPILE_FLAGS) $(C_INCLUDE)