diff --git a/doc/BUILDING-external-libs.md b/doc/BUILDING-external-libs.md
index 29a9d02..e95d6c7 100644
--- a/doc/BUILDING-external-libs.md
+++ b/doc/BUILDING-external-libs.md
@@ -8,7 +8,7 @@ replacing "32" with "64".
 ## Prepare Ubuntu environment
 
 ```
-sudo apt-get install build-essential cmake tofrodos
+sudo apt-get install build-essential cmake tofrodos libtool-bin
 sudo mkdir /opt/android
 sudo chown $LOGNAME /opt/android
 ```
@@ -70,9 +70,9 @@ ln -s ../../../../openssl/android-21/lib/libcrypto.so
 ## Build Boost
 ```
 cd /opt/android
-wget https://sourceforge.net/projects/boost/files/boost/1.64.0/boost_1_64_0.tar.gz/download -O boost_1_64_0.tar.gz
-tar xfz boost_1_64_0.tar.gz
-(cd boost_1_64_0; ./bootstrap.sh)
+wget https://sourceforge.net/projects/boost/files/boost/1.58.0/boost_1_58_0.tar.gz/download -O boost_1_58_0.tar.gz
+tar xfz boost_1_58_0.tar.gz
+(cd boost_1_58_0; ./bootstrap.sh)
 ```
 The NDK r15c above gives errors about fsetpos and fgetpos not found(!?!), so we "just" comment them out in the include file:
 `nano /opt/android/tool32/include/c++/4.9.x/cstdio` (`//using ::fgetpos`, `//using ::fsetpos`)
@@ -83,21 +83,51 @@ export PATH=/opt/android/tool32/arm-linux-androideabi/bin:/opt/android/tool32/bi
 ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --build-dir=android32 --stagedir=android32 toolset=clang threading=multi threadapi=pthread target-os=android stage
 ```
 
+## Build & prepare zeromq
+```
+cd /opt/android
+wget git clone https://github.com/zeromq/zeromq3-x.git
+export PATH=/opt/android/tool32/arm-linux-androideabi/bin:/opt/android/tool32/bin:$PATH
+export OUTPUT_DIR=/opt/android/zeromq
+./configure --enable-static --disable-shared --host=arm-linux-androideabi --prefix=$OUTPUT_DIR LDFLAGS="-L$OUTPUT_DIR/lib" CPPFLAGS="-isystem /opt/android/tool32/include/c++/4.9.x -fPIC -I$OUTPUT_DIR/include -Wno-error -D__ANDROID_API__=21" LIBS="-lgcc"
+make
+make install
+
+git clone https://github.com/zeromq/cppzmq.git
+ cp cppzmq/*.hpp zeromq/include/
+```
+
 ## And finally: Build Monero
 ```
 cd /opt/android
 git clone https://github.com/monero-project/monero
 cd monero
-
+```
+```
 # <patch monero code as needed>
-
+# also, don't abort on warnings:
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 1f74f59..2c791c0 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -400,7 +400,7 @@ else()
+     set(ARCH_FLAG "-march=${ARCH}")
+   endif()
+   set(WARNINGS "-Wall -Wextra -Wpointer-arith -Wundef -Wvla -Wwrite-strings -Wno-error=extra -Wno-error=deprecated-declarations -Wno-unused-parameter -Wno-unused-variable -Wno-error=unused-variable -Wno-error=undef -Wno-error=uninitialized")
+-  if(NOT MINGW)
++  if(NOT MINGW AND NOT ANDROID)
+     set(WARNINGS_AS_ERRORS_FLAG "-Werror")
+   endif()
+   if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
+```
+```
 mkdir -p build/release.android32
 cd build/release.android32
 
 # only if not set already set
 export PATH=/opt/android/tool32/arm-linux-androideabi/bin:/opt/android/tool32/bin:$PATH
 
-CC=clang CXX=clang++ cmake -D BUILD_TESTS=OFF -D ARCH="armv7-a" -D STATIC=ON -D BUILD_64=OFF -D CMAKE_BUILD_TYPE=release -D ANDROID=true -D BUILD_TAG="android" -D BOOST_ROOT=/opt/android/boost_1_64_0 -D BOOST_LIBRARYDIR=/opt/android/boost_1_64_0/android32/lib  -D OPENSSL_ROOT_DIR=/opt/android/openssl/android-21 -D CMAKE_POSITION_INDEPENDENT_CODE:BOOL=true ../..
+CC=clang CXX=clang++ cmake -D BUILD_TESTS=OFF -D ARCH="armv7-a" -D STATIC=ON -D BUILD_64=OFF -D CMAKE_BUILD_TYPE=release -D ANDROID=true -D BUILD_TAG="android" -D BOOST_ROOT=/opt/android/boost_1_58_0 -D BOOST_LIBRARYDIR=/opt/android/boost_1_58_0/android32/lib  -D OPENSSL_ROOT_DIR=/opt/android/openssl/android-21 -D CMAKE_POSITION_INDEPENDENT_CODE:BOOL=true -D ZMQ_INCLUDE_PATH=/opt/android/zeromq/include -D ZMQ_LIB=/opt/android/zeromq/lib/libzmq.a ../..
 make
 
 find . -name '*.a' -exec cp '{}' lib \;