diff --git a/net-im/libsignal/Makefile b/net-im/libsignal/Makefile
index 52fdc8980b90..60c1b12443aa 100644
--- a/net-im/libsignal/Makefile
+++ b/net-im/libsignal/Makefile
@@ -1,49 +1,53 @@
 PORTNAME=	libsignal
 DISTVERSIONPREFIX=	v
 DISTVERSION=	0.96.4
 CATEGORIES=	net-im java
 
 MAINTAINER=	jaap.aarts1@gmail.com
 COMMENT=	Implementation of the Signal client protocol
 WWW=		https://github.com/signalapp/libsignal
 
 LICENSE=	AGPLv3
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
 BUILD_DEPENDS=	llvm-config${LLVM_DEFAULT}:devel/llvm${LLVM_DEFAULT} \
 		protoc:devel/protobuf
 
 USES=		cargo
+
+# BoringSSL ships no PowerPC assembly, so use the portable C implementations.
+CFLAGS_powerpc64le=	-DOPENSSL_NO_ASM
+CXXFLAGS_powerpc64le=	-DOPENSSL_NO_ASM
 USE_GITHUB=	yes
 GH_ACCOUNT=	signalapp
 BROKEN_i386= 	bindgen for boring-ssl fail
 #CFLAGS_i386=	-DOPENSSL_NO_ASM
 USE_LDCONFIG=	yes
 
 # to get the GH_TUPLE
 # git clone git@github.com:signalapp/boring.git
 # cd boring
 # git checkout correct_tag (grep boring Makefile.crates)
 # git submodule update --init --recursive
 # the hash for boringssl and fips should be printed on screen
 # or browse https://github.com/signalapp/boring/tree/signal-v4.15.0/boring-sys/deps (with the correct tag)
 GH_TUPLE=	google:boringssl:91a66a59b6c1435120ff83e245d7719411294386:boringssl \
 
 CARGO_BUILD_ARGS=	--package libsignal-jni --package libsignal-ffi
 MAKE_ENV=		CARGO_PROFILE_RELEASE_LTO=thin \
 			OPENSSL_INCLUDE_DIR=${OPENSSLINC} \
 			OPENSSL_LIB_DIR=${OPENSSLLIB} \
 			RUSTC_BOOTSTRAP=aes,polyval
 
 .include <bsd.port.options.mk>
 
 post-extract:
 	${MV} ${WRKDIR}/boringssl-91a66a59b6c1435120ff83e245d7719411294386/* ${WRKDIR}/boring-signal-v5.0.2/boring-sys/deps/boringssl
 
 do-install:
 	${INSTALL_DATA} ${CARGO_TARGET_DIR}/*/libsignal_ffi.a \
 		${STAGEDIR}${PREFIX}/lib/
 	${INSTALL_LIB} ${CARGO_TARGET_DIR}/*/libsignal_jni.so \
 		${STAGEDIR}${PREFIX}/lib/
 
 .include <bsd.port.mk>
diff --git a/net-im/libsignal/files/patch-boringssl_include_openssl_target.h b/net-im/libsignal/files/patch-boringssl_include_openssl_target.h
new file mode 100644
index 000000000000..17ab72a00d04
--- /dev/null
+++ b/net-im/libsignal/files/patch-boringssl_include_openssl_target.h
@@ -0,0 +1,14 @@
+--- ../boring-signal-v5.0.2/boring-sys/deps/boringssl/include/openssl/target.h.orig
++++ ../boring-signal-v5.0.2/boring-sys/deps/boringssl/include/openssl/target.h
+@@ -54,6 +54,11 @@
+ #define OPENSSL_32_BIT
+ #elif defined(__myriad2__)
+ #define OPENSSL_32_BIT
++#elif defined(__powerpc64__)
++// PowerPC64 has no BoringSSL assembly; the portable C code is used and the
++// build must define OPENSSL_NO_ASM.  BoringSSL only officially supports
++// little-endian, so big-endian ppc64 is unverified.
++#define OPENSSL_64_BIT
+ #else
+ // The list above enumerates the platforms that BoringSSL supports. For these
+ // platforms we keep a reasonable bar of not breaking them: automated test