diff --git a/zorg/buildbot/builders/sanitizers/buildbot_android.sh b/zorg/buildbot/builders/sanitizers/buildbot_android.sh
--- a/zorg/buildbot/builders/sanitizers/buildbot_android.sh
+++ b/zorg/buildbot/builders/sanitizers/buildbot_android.sh
@@ -25,7 +25,7 @@
 
 clobber
 
-download_android_tools r16
+download_android_tools r21
 
 # Stage 1
 
diff --git a/zorg/buildbot/builders/sanitizers/buildbot_android_functions.sh b/zorg/buildbot/builders/sanitizers/buildbot_android_functions.sh
--- a/zorg/buildbot/builders/sanitizers/buildbot_android_functions.sh
+++ b/zorg/buildbot/builders/sanitizers/buildbot_android_functions.sh
@@ -52,7 +52,7 @@
   local _ndk_arch=$2
   if [[ ! -d $NDK_DIR/standalone-$_arch ]] ; then 
     echo @@@BUILD_STEP building Android NDK for $_arch@@@
-    $NDK_DIR/build/tools/make_standalone_toolchain.py --api 24 --force --arch $_ndk_arch --stl=libc++ --install-dir $NDK_DIR/standalone-$_arch
+    $NDK_DIR/build/tools/make_standalone_toolchain.py --api $ANDROID_API --force --arch $_ndk_arch --stl=libc++ --install-dir $NDK_DIR/standalone-$_arch
   fi
 }
 
@@ -61,11 +61,14 @@
   local _triple=$2
 
   local ANDROID_TOOLCHAIN=$ROOT/android_ndk/standalone-$_arch
+  local ANDROID_LIB=$ANDROID_TOOLCHAIN/sysroot/usr/lib/$_arch-linux-android/$ANDROID_API
   local ANDROID_LIBRARY_OUTPUT_DIR=$(ls -d $ROOT/llvm_build64/lib/clang/* | tail -1)
   local ANDROID_EXEC_OUTPUT_DIR=$ROOT/llvm_build64/bin
-  local ANDROID_FLAGS="--target=$_triple --sysroot=$ANDROID_TOOLCHAIN/sysroot -B$ANDROID_TOOLCHAIN"
-  local ANDROID_CXX_FLAGS="$ANDROID_FLAGS -stdlib=libstdc++"
+  local ANDROID_FLAGS="--target=$_triple -B$ANDROID_TOOLCHAIN -B$ANDROID_LIB -I/$ANDROID_TOOLCHAIN/sysroot/usr/include/c++/v1 "
+  local ANDROID_CXX_FLAGS="$ANDROID_FLAGS -stdlib=libstdc++ "
 
+  local CLANG_PATH=$ROOT/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/bin/$_arch-linux-android$ANDROID_API-clang
+  local CLANGXX_PATH=$ROOT/android_ndk/toolchains/llvm/prebuilt/linux-x86_64/bin/$_arch-linux-android$ANDROID_API-clang++
   # Always clobber android build tree.
   # It has a hidden dependency on clang (through CXX) which is not known to
   # the build system.
@@ -76,8 +79,8 @@
 
   (cd llvm_build_android_$_arch && cmake \
     -DLLVM_ENABLE_WERROR=OFF \
-    -DCMAKE_C_COMPILER=$ROOT/llvm_build64/bin/clang \
-    -DCMAKE_CXX_COMPILER=$ROOT/llvm_build64/bin/clang++ \
+    -DCMAKE_C_COMPILER=$CLANG_PATH \
+    -DCMAKE_CXX_COMPILER=$CLANGXX_PATH \
     -DCMAKE_ASM_FLAGS="$ANDROID_FLAGS" \
     -DCMAKE_C_FLAGS="$ANDROID_FLAGS" \
     -DCMAKE_CXX_FLAGS="$ANDROID_CXX_FLAGS" \
@@ -91,8 +94,8 @@
   local COMPILER_RT_OPTIONS="$(readlink -f $LLVM/../compiler-rt)"
   
   (cd compiler_rt_build_android_$_arch && cmake \
-    -DCMAKE_C_COMPILER=$ROOT/llvm_build64/bin/clang \
-    -DCMAKE_CXX_COMPILER=$ROOT/llvm_build64/bin/clang++ \
+    -DCMAKE_C_COMPILER=$CLANG_PATH \
+    -DCMAKE_CXX_COMPILER=$CLANGXX_PATH \
     -DLLVM_CONFIG_PATH=$ROOT/llvm_build64/bin/llvm-config \
     -DCOMPILER_RT_BUILD_BUILTINS=OFF \
     -DCOMPILER_RT_INCLUDE_TESTS=ON \
@@ -101,6 +104,7 @@
     -DCMAKE_C_FLAGS="$ANDROID_FLAGS" \
     -DCMAKE_CXX_FLAGS="$ANDROID_CXX_FLAGS" \
     -DANDROID=1 \
+    -DANDROID_HAS_ELF_TLS=1 \
     -DCOMPILER_RT_TEST_COMPILER_CFLAGS="$ANDROID_FLAGS" \
     -DCOMPILER_RT_TEST_TARGET_TRIPLE=$_triple \
     -DCOMPILER_RT_OUTPUT_DIR="$ANDROID_LIBRARY_OUTPUT_DIR" \