diff --git a/lib/libthr/Makefile b/lib/libthr/Makefile
index 85c028f521a1..d3c69a7dc8b7 100644
--- a/lib/libthr/Makefile
+++ b/lib/libthr/Makefile
@@ -1,98 +1,102 @@
 
 PACKAGE=	clibs
 SHLIBDIR?= /lib
 
 LIBADD=	c sys
 .if defined(COMPAT_libcompat)
 # XXX: work around gcc -m32 + bfd ld path issue for DT_NEEDED symbols.
 # https://sourceware.org/bugzilla/show_bug.cgi?id=31395
 LDFLAGS+=	-Wl,--rpath=/usr/lib${COMPAT_libcompat}
 .endif
 
 .include <src.opts.mk>
 MK_SSP=	no
 # SSP forced off already implies FORTIFY_SOURCE=0, but we must make sure that
 # one cannot turn it back on.
 FORTIFY_SOURCE=	0
 
 LIB=thr
 SHLIB_MAJOR= 3
 
 NO_WTHREAD_SAFETY=1
 NO_WCAST_ALIGN.gcc=1    # for gcc 4.2
 CFLAGS+=-DPTHREAD_KERNEL
 CFLAGS+=-I${SRCTOP}/lib/libc/include
 CFLAGS+=-I${SRCTOP}/lib/libc/${MACHINE_CPUARCH}
 CFLAGS+=-I${.CURDIR}/thread
 CFLAGS+=-I${.CURDIR}/arch/${MACHINE_CPUARCH}/include
 CFLAGS+=-I${.CURDIR}/sys
 CFLAGS+=-I${SRCTOP}/libexec/rtld-elf
 CFLAGS+=-I${SRCTOP}/libexec/rtld-elf/${MACHINE_CPUARCH}
 CFLAGS+=-I${SRCTOP}/lib/libthread_db
 
 CFLAGS.thr_stack.c+=	-Wno-cast-align
 CFLAGS.rtld_malloc.c+=	-Wno-cast-align
+# Disable compiler builtins so that the compiler does not optimize away rtld's
+# attempts to force early PLT resolution for certain functions that may be
+# replaced by builtins.
+CFLAGS.thr_rtld.c+=	-fno-builtin
 CFLAGS.thr_symbols.c+=	-Wno-missing-variable-declarations
 .if ${MK_ASAN} != "no"
 # False-positive ASAN error claiming the local "struct sigaction act;" is
 # overflowed by handle_signal() reading from the ucontext_t argument. This
 # could be caused by ASAN not treating this function as a signal handler.
 CFLAGS.thr_sig.c+=	-fno-sanitize=address
 .endif
 
 .if ${MACHINE_CPUARCH} == "arm"
 NO_THREAD_UNWIND_STACK= yes
 .endif
 
 .ifndef NO_THREAD_UNWIND_STACK
 CFLAGS+=-fexceptions
 CFLAGS+=-D_PTHREAD_FORCED_UNWIND
 .endif
 
 LDFLAGS+=-Wl,-znodelete
 LDFLAGS+=-Wl,--auxiliary,libsys.so.7
 
 VERSION_DEF=${SRCTOP}/lib/libc/Versions.def
 SYMBOL_MAPS=${.CURDIR}/pthread.map
 
 MAN=	libthr.3
 
 .if ${MK_PTHREADS_ASSERTIONS} != "no"
 # enable extra internal consistency checks
 CFLAGS+=-D_PTHREADS_INVARIANTS
 .endif
 
 PRECIOUSLIB=
 
 .PATH: ${.CURDIR}/arch/${MACHINE_CPUARCH}/${MACHINE_CPUARCH}
 .PATH: ${SRCTOP}/libexec/rtld-elf
 
 .if exists(${.CURDIR}/arch/${MACHINE_CPUARCH}/Makefile.inc)
 .include "${.CURDIR}/arch/${MACHINE_CPUARCH}/Makefile.inc"
 .endif
 .include "${.CURDIR}/sys/Makefile.inc"
 .include "${.CURDIR}/thread/Makefile.inc"
 SRCS+= rtld_malloc.c
 
 LIBSYS_SRCTOP=	${.CURDIR:H}/libsys
 .if exists(${LIBSYS_SRCTOP}/${MACHINE_CPUARCH}/_umtx_op_err.S)
 .PATH: ${LIBSYS_SRCTOP}/${MACHINE_CPUARCH}
 .else
 .PATH: ${LIBSYS_SRCTOP}
 .endif
 OBJS+=	_umtx_op_err.o
 
 .if ${MK_INSTALLLIB} != "no"
 SYMLINKS+=lib${LIB}.a ${LIBDIR}/libpthread.a
 .endif
 .if !defined(NO_PIC)
 SYMLINKS+=lib${LIB}.so ${LIBDIR}/libpthread.so
 .endif
 .if ${MK_PROFILE} != "no"
 SYMLINKS+=lib${LIB}_p.a ${LIBDIR}/libpthread_p.a
 .endif
 
 HAS_TESTS=
 SUBDIR.${MK_TESTS}+= tests
 
 .include <bsd.lib.mk>