diff -u -r ../sslscan-1.11.7-rbsec/Makefile ./Makefile
--- ../sslscan-1.11.7-rbsec/Makefile	2016-06-13 08:42:11.000000000 -0400
+++ ./Makefile	2016-09-05 16:37:59.831058901 -0400
@@ -14,7 +14,7 @@
 OS := $(shell uname)
 
 SRCS      = sslscan.c
-PREFIX    = /usr
+PREFIX    ?= /usr
 BINDIR    = $(PREFIX)/bin
 MANDIR    = $(PREFIX)/share/man
 MAN1DIR   = $(MANDIR)/man1