diff --git a/contrib/gitian-descriptors/gitian-osx.yml b/contrib/gitian-descriptors/gitian-osx.yml
index 3db1048907..cb82bc18b8 100644
--- a/contrib/gitian-descriptors/gitian-osx.yml
+++ b/contrib/gitian-descriptors/gitian-osx.yml
@@ -32,10 +32,10 @@ remotes:
 - "url": "https://github.com/firoorg/firo"
   "dir": "firo"
 files:
-- "MacOSX10.11.sdk.tar.gz"
+- "MacOSX10.14.sdk.tar.gz"
 script: |
   WRAP_DIR=$HOME/wrapped
-  HOSTS="x86_64-apple-darwin14"
+  HOSTS="x86_64-apple-darwin16"
   CONFIGFLAGS="--enable-reduce-exports --disable-bench --disable-gui-tests GENISOIMAGE=$WRAP_DIR/genisoimage --enable-crash-hooks"
   FAKETIME_HOST_PROGS=""
   FAKETIME_PROGS="ar ranlib date dmg genisoimage"
@@ -88,7 +88,7 @@ script: |
   BASEPREFIX=`pwd`/depends
 
   mkdir -p ${BASEPREFIX}/SDKs
-  tar -C ${BASEPREFIX}/SDKs -xf ${BUILD_DIR}/MacOSX10.11.sdk.tar.gz
+  tar -C ${BASEPREFIX}/SDKs -xf ${BUILD_DIR}/MacOSX10.14.sdk.tar.gz
 
   # Build dependencies for each host
   for i in $HOSTS; do
@@ -167,5 +167,5 @@ script: |
   done
   mkdir -p $OUTDIR/src
   mv $SOURCEDIST $OUTDIR/src
-  mv ${OUTDIR}/${DISTNAME}-x86_64-apple-darwin14.tar.gz ${OUTDIR}/${DISTNAME}-osx64.tar.gz
-  mv ${OUTDIR}/${DISTNAME}-x86_64-apple-darwin14-debug.tar.gz ${OUTDIR}/${DISTNAME}-osx64-debug.tar.gz
+  mv ${OUTDIR}/${DISTNAME}-x86_64-apple-darwin16.tar.gz ${OUTDIR}/${DISTNAME}-osx64.tar.gz
+  mv ${OUTDIR}/${DISTNAME}-x86_64-apple-darwin16-debug.tar.gz ${OUTDIR}/${DISTNAME}-osx64-debug.tar.gz
diff --git a/depends/hosts/darwin.mk b/depends/hosts/darwin.mk
index 4e58bec74e..1bc4fb8189 100644
--- a/depends/hosts/darwin.mk
+++ b/depends/hosts/darwin.mk
@@ -1,9 +1,8 @@
-OSX_MIN_VERSION=10.8
-OSX_SDK_VERSION=10.11
+OSX_MIN_VERSION=10.12
+OSX_SDK_VERSION=10.14
 OSX_SDK=$(SDK_PATH)/MacOSX$(OSX_SDK_VERSION).sdk
-LD64_VERSION=253.9
-darwin_CC=clang -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK) -mlinker-version=$(LD64_VERSION)
-darwin_CXX=clang++ -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK) -mlinker-version=$(LD64_VERSION) -stdlib=libc++
+darwin_CC=clang -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK)
+darwin_CXX=clang++ -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK) -stdlib=libc++
 
 darwin_CFLAGS=-pipe
 darwin_CXXFLAGS=$(darwin_CFLAGS)
diff --git a/depends/packages/native_cctools.mk b/depends/packages/native_cctools.mk
index 44d238cc4c..4195230b40 100644
--- a/depends/packages/native_cctools.mk
+++ b/depends/packages/native_cctools.mk
@@ -1,45 +1,55 @@
 package=native_cctools
-$(package)_version=807d6fd1be5d2224872e381870c0a75387fe05e6
-$(package)_download_path=https://github.com/theuni/cctools-port/archive
+$(package)_version=3764b223c011574971ee3ae09ce968ba5dc2f00f
+$(package)_download_path=https://github.com/tpoechtrager/cctools-port/archive
 $(package)_file_name=$($(package)_version).tar.gz
-$(package)_sha256_hash=a09c9ba4684670a0375e42d9d67e7f12c1f62581a27f28f7c825d6d7032ccc6a
+$(package)_sha256_hash=3e35907bf376269a844df08e03cbb43e345c88125374f2228e03724b5f9a2a04
 $(package)_build_subdir=cctools
-$(package)_clang_version=3.7.1
-$(package)_clang_download_path=http://llvm.org/releases/$($(package)_clang_version)
+$(package)_clang_version=6.0.1
+$(package)_clang_download_path=https://releases.llvm.org/$($(package)_clang_version)
 $(package)_clang_download_file=clang+llvm-$($(package)_clang_version)-x86_64-linux-gnu-ubuntu-14.04.tar.xz
 $(package)_clang_file_name=clang-llvm-$($(package)_clang_version)-x86_64-linux-gnu-ubuntu-14.04.tar.xz
-$(package)_clang_sha256_hash=99b28a6b48e793705228a390471991386daa33a9717cd9ca007fcdde69608fd9
+$(package)_clang_sha256_hash=fa5416553ca94a8c071a27134c094a5fb736fe1bd0ecc5ef2d9bc02754e1bef0
+
+$(package)_libtapi_version=3efb201881e7a76a21e0554906cf306432539cef
+$(package)_libtapi_download_path=https://github.com/tpoechtrager/apple-libtapi/archive
+$(package)_libtapi_download_file=$($(package)_libtapi_version).tar.gz
+$(package)_libtapi_file_name=$($(package)_libtapi_version).tar.gz
+$(package)_libtapi_sha256_hash=380c1ca37cfa04a8699d0887a8d3ee1ad27f3d08baba78887c73b09485c0fbd3
+
 $(package)_extra_sources=$($(package)_clang_file_name)
+$(package)_extra_sources += $($(package)_libtapi_file_name)
 
 define $(package)_fetch_cmds
 $(call fetch_file,$(package),$($(package)_download_path),$($(package)_download_file),$($(package)_file_name),$($(package)_sha256_hash)) && \
-$(call fetch_file,$(package),$($(package)_clang_download_path),$($(package)_clang_download_file),$($(package)_clang_file_name),$($(package)_clang_sha256_hash))
+$(call fetch_file,$(package),$($(package)_clang_download_path),$($(package)_clang_download_file),$($(package)_clang_file_name),$($(package)_clang_sha256_hash)) && \
+$(call fetch_file,$(package),$($(package)_libtapi_download_path),$($(package)_libtapi_download_file),$($(package)_libtapi_file_name),$($(package)_libtapi_sha256_hash))
 endef
 
 define $(package)_extract_cmds
   mkdir -p $($(package)_extract_dir) && \
   echo "$($(package)_sha256_hash)  $($(package)_source)" > $($(package)_extract_dir)/.$($(package)_file_name).hash && \
   echo "$($(package)_clang_sha256_hash)  $($(package)_source_dir)/$($(package)_clang_file_name)" >> $($(package)_extract_dir)/.$($(package)_file_name).hash && \
+  echo "$($(package)_libtapi_sha256_hash)  $($(package)_source_dir)/$($(package)_libtapi_file_name)" >> $($(package)_extract_dir)/.$($(package)_file_name).hash && \
   $(build_SHA256SUM) -c $($(package)_extract_dir)/.$($(package)_file_name).hash && \
-  mkdir -p toolchain/bin toolchain/lib/clang/3.5/include && \
-  tar --strip-components=1 -C toolchain -xf $($(package)_source_dir)/$($(package)_clang_file_name) && \
+  mkdir -p toolchain/bin toolchain/lib/clang/$($(package)_clang_version)/include && \
+  mkdir -p libtapi && \
+  tar --no-same-owner --strip-components=1 -C libtapi -xf $($(package)_source_dir)/$($(package)_libtapi_file_name) && \
+  tar --no-same-owner --strip-components=1 -C toolchain -xf $($(package)_source_dir)/$($(package)_clang_file_name) && \
   rm -f toolchain/lib/libc++abi.so* && \
-  echo "#!/bin/sh" > toolchain/bin/$(host)-dsymutil && \
-  echo "exit 0" >> toolchain/bin/$(host)-dsymutil && \
-  chmod +x toolchain/bin/$(host)-dsymutil && \
-  tar --strip-components=1 -xf $($(package)_source)
+  tar --no-same-owner --strip-components=1 -xf $($(package)_source)
 endef
 
 define $(package)_set_vars
-$(package)_config_opts=--target=$(host) --disable-lto-support
-$(package)_ldflags+=-Wl,-rpath=\\$$$$$$$$\$$$$$$$$ORIGIN/../lib
-$(package)_cc=$($(package)_extract_dir)/toolchain/bin/clang
-$(package)_cxx=$($(package)_extract_dir)/toolchain/bin/clang++
+  $(package)_config_opts=--target=$(host) --disable-lto-support --with-libtapi=$($(package)_extract_dir)
+  $(package)_ldflags+=-Wl,-rpath=\\$$$$$$$$\$$$$$$$$ORIGIN/../lib
+  $(package)_cc=$($(package)_extract_dir)/toolchain/bin/clang
+  $(package)_cxx=$($(package)_extract_dir)/toolchain/bin/clang++
 endef
 
 define $(package)_preprocess_cmds
-  cd $($(package)_build_subdir); ./autogen.sh && \
-  sed -i.old "/define HAVE_PTHREADS/d" ld64/src/ld/InputFiles.h
+  CC=$($(package)_cc) CXX=$($(package)_cxx) INSTALLPREFIX=$($(package)_extract_dir) ./libtapi/build.sh && \
+  CC=$($(package)_cc) CXX=$($(package)_cxx) INSTALLPREFIX=$($(package)_extract_dir) ./libtapi/install.sh && \
+  sed -i.old "/define HAVE_PTHREADS/d" $($(package)_build_subdir)/ld64/src/ld/InputFiles.h
 endef
 
 define $(package)_config_cmds
@@ -52,6 +62,9 @@ endef
 
 define $(package)_stage_cmds
   $(MAKE) DESTDIR=$($(package)_staging_dir) install && \
+  mkdir -p $($(package)_staging_prefix_dir)/lib/ && \
+  cd $($(package)_extract_dir) && \
+  cp lib/libtapi.so.6 $($(package)_staging_prefix_dir)/lib/ && \
   cd $($(package)_extract_dir)/toolchain && \
   mkdir -p $($(package)_staging_prefix_dir)/lib/clang/$($(package)_clang_version)/include && \
   mkdir -p $($(package)_staging_prefix_dir)/bin $($(package)_staging_prefix_dir)/include && \
diff --git a/src/Makefile.am b/src/Makefile.am
index ac32620071..708f21ab0d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -820,7 +820,7 @@ if GLIBC_BACK_COMPAT
   libbitcoinconsensus_la_SOURCES += compat/glibc_compat.cpp
 endif
 
-libbitcoinconsensus_la_LDFLAGS = $(AM_LDFLAGS) $(RELDFLAGS) $(LIBBLSSIG_LIBS) $(LIBBLSSIG_DEPENDS)
+libbitcoinconsensus_la_LDFLAGS = $(AM_LDFLAGS) -no-undefined $(RELDFLAGS) $(LIBBLSSIG_LIBS) $(LIBBLSSIG_DEPENDS)
 libbitcoinconsensus_la_LIBADD = $(LIBSECP256K1)
 libbitcoinconsensus_la_CPPFLAGS = $(AM_CPPFLAGS) -I$(builddir)/obj -I$(srcdir)/secp256k1/include $(LIBBLSSIG_INCLUDES) -DBUILD_BITCOIN_INTERNAL
 libbitcoinconsensus_la_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)