Index: share/mk/bsd.sys.mk
===================================================================
--- share/mk/bsd.sys.mk
+++ share/mk/bsd.sys.mk
@@ -131,11 +131,6 @@
 		-Wno-error=unused-value
 .endif
 
-# GCC 5.3.0
-.if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 50300
-CWARNFLAGS+=	-Wno-error=strict-overflow
-.endif
-
 # GCC 6.1.0
 .if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 60100
 CWARNFLAGS+=	-Wno-error=misleading-indentation	\
Index: sys/conf/kern.mk
===================================================================
--- sys/conf/kern.mk
+++ sys/conf/kern.mk
@@ -58,7 +58,6 @@
 		-Wno-error=maybe-uninitialized			\
 		-Wno-error=overflow				\
 		-Wno-error=sequence-point			\
-		-Wno-error=strict-overflow			\
 		-Wno-error=unused-but-set-variable
 .if ${COMPILER_VERSION} >= 60100
 CWARNEXTRA+=	-Wno-error=misleading-indentation		\
Index: usr.sbin/zic/zic/Makefile
===================================================================
--- usr.sbin/zic/zic/Makefile
+++ usr.sbin/zic/zic/Makefile
@@ -1,5 +1,7 @@
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 .PATH: ${SRCTOP}/contrib/tzcode/zic
 
 PROG=	zic
@@ -13,4 +15,8 @@
 
 WARNS?=	2
 
+.if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 50300
+CWARNFLAGS+=	-Wno-error=strict-overflow
+.endif
+
 .include <bsd.prog.mk>