--- Makefile.orig	2018-11-29 14:45:26 UTC
+++ Makefile
@@ -29,7 +29,7 @@ EXE = stockfish
 endif
 
 ### Installation dir definitions
-PREFIX = /usr/local
+PREFIX ?= /usr/local
 BINDIR = $(PREFIX)/bin
 
 ### Built-in benchmark for pgo-builds
@@ -211,7 +211,9 @@ ifeq ($(COMP),clang)
 
 	ifneq ($(KERNEL),Darwin)
 	ifneq ($(KERNEL),OpenBSD)
+	ifneq ($(KERNEL),FreeBSD)
 		LDFLAGS += -latomic
+	endif
 	endif
 	endif