diff --git a/Makefile b/Makefile
--- a/Makefile
+++ b/Makefile
@@ -155,6 +155,7 @@
 
 TGTS=	all all-man buildenv buildenvvars buildetc buildkernel buildworld \
 	check check-old check-old-dirs check-old-files check-old-libs \
+	check-symbols \
 	checkdpadd checkworld clean cleandepend cleandir cleankernel \
 	cleanworld cleanuniverse \
 	delete-old delete-old-dirs delete-old-files delete-old-libs \
diff --git a/share/mk/bsd.lib.mk b/share/mk/bsd.lib.mk
--- a/share/mk/bsd.lib.mk
+++ b/share/mk/bsd.lib.mk
@@ -375,6 +375,38 @@
 ${SHLIB_NAME}.debug: ${SHLIB_NAME_FULL}
 	${OBJCOPY} --only-keep-debug ${SHLIB_NAME_FULL} ${.TARGET}
 .endif
+
+CLEANFILES+=	${SHLIB_NAME}.symbols
+${SHLIB_NAME}.symbols: ${SHLIB_NAME_FULL}
+	(printf "%sgenerated by bsd.lib.mk\n" @; \
+	 objdump -T ${.ALLSRC} | grep -v '\*UND\*' | cut -f 2 | grep '^0' | \
+	    sed -e 's/^[0-9a-z]*  *//' | \
+	    awk '{ if ($$2 == "") { print $$1 " <unversioned>" } else if ($$3 == "") { print $$2 " " $$1 } else { print $$3 " " $$1 } }' | \
+	    sort) > ${.TARGET}
+
+.if defined(SYMBOLS_REF_MD)
+_SYMBOLS_REF_ARCH=-${MACHINE_ARCH}
+.else
+_SYMBOLS_REF_ARCH=
+.endif
+SYMBOLS_REF?=	${.CURDIR}/${SHLIB_NAME}.symref${_SYMBOLS_REF_ARCH}
+.if ${.TARGETS:Mcheck-symbols}
+_CHECK_SYMBOLS_WARNING?=echo
+.else
+_CHECK_SYMBOLS_WARNING?=true
+.endif
+check-symbols: ${SHLIB_NAME}.symbols
+	@if [ ! -e ${SYMBOLS_REF} ]; then \
+		${_CHECK_SYMBOLS_WARNING} "WARNING: no symbol reference (${SYMBOLS_REF:T}), run 'make update-symref'" 1>&2; \
+	else \
+		if ! diff ${SYMBOLS_REF} ${SHLIB_NAME}.symbols; then \
+			echo "ERROR: symbol set changed, correct or run 'make update-symref'" 1>&2; \
+			false; \
+		fi \
+	fi
+
+update-symref: ${SHLIB_NAME}.symbols
+	cp ${SHLIB_NAME}.symbols ${SYMBOLS_REF}
 .endif #defined(SHLIB_NAME)
 
 .if defined(INSTALL_PIC_ARCHIVE) && defined(LIB) && !empty(LIB)
diff --git a/share/mk/bsd.subdir.mk b/share/mk/bsd.subdir.mk
--- a/share/mk/bsd.subdir.mk
+++ b/share/mk/bsd.subdir.mk
@@ -41,7 +41,8 @@
 
 SUBDIR_TARGETS+= \
 		all all-man analyze buildconfig buildfiles buildincludes \
-		checkdpadd clean cleandepend cleandir cleanilinks \
+		checkdpadd check-symbols \
+		clean cleandepend cleandir cleanilinks \
 		cleanobj depend distribute files includes installconfig \
 		installdirs \
 		installfiles installincludes print-dir realinstall \