diff -ur a/bandwidth2/Makefile b/bandwidth2/Makefile
--- a/bandwidth2/Makefile	2021-02-02 07:03:47.002894030 -0600
+++ b/bandwidth2/Makefile	2021-02-02 07:05:21.556854777 -0600
@@ -1,6 +1,6 @@
 P=bandwidth2
 OBJECTS=
-CFLAGS=-g -Wall -Werror -O2 -std=c11
+CFLAGS ?= -g -Wall -Werror -O2 -std=c11
 LDLIBS=
 
 $(P): $(OBJECTS)
diff -ur a/cpu_usage2/Makefile b/cpu_usage2/Makefile
--- a/cpu_usage2/Makefile	2021-02-02 07:03:47.004894029 -0600
+++ b/cpu_usage2/Makefile	2021-02-02 07:05:51.138842328 -0600
@@ -1,6 +1,6 @@
 P=cpu_usage2
 OBJECTS=
-CFLAGS=-g -Wall -Werror -O2 -std=gnu11
+CFLAGS ?= -g -Wall -Werror -O2 -std=gnu11
 LDLIBS=
 
 $(P): $(OBJECTS)