diff --git a/Dockerfile.dev b/Dockerfile.dev
index 47146d3..db102e0 100644
--- a/Dockerfile.dev
+++ b/Dockerfile.dev
@@ -36,6 +36,10 @@ RUN ./build-mingw-w64.sh $TOOLCHAIN_PREFIX
 COPY build-compiler-rt.sh .
 RUN ./build-compiler-rt.sh $TOOLCHAIN_PREFIX
 
+# Build mingw-w64's winpthreads
+COPY build-mingw-w64-winpthreads.sh .
+RUN ./build-mingw-w64-winpthreads.sh $TOOLCHAIN_PREFIX
+
 # Build C test applications
 ENV PATH=$TOOLCHAIN_PREFIX/bin:$PATH
 
diff --git a/build-all.sh b/build-all.sh
index 5cff3a8..fa4d663 100755
--- a/build-all.sh
+++ b/build-all.sh
@@ -12,5 +12,6 @@ PREFIX="$1"
 ./install-wrappers.sh $PREFIX
 ./build-mingw-w64.sh $PREFIX
 ./build-compiler-rt.sh $PREFIX
+./build-mingw-w64-winpthreads.sh $PREFIX
 ./build-libcxx.sh $PREFIX
 ./build-libssp.sh $PREFIX
diff --git a/build-mingw-w64-winpthreads.sh b/build-mingw-w64-winpthreads.sh
new file mode 100755
index 0000000..ba760fd
--- /dev/null
+++ b/build-mingw-w64-winpthreads.sh
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -e
+
+if [ $# -lt 1 ]; then
+    echo $0 dest
+    exit 1
+fi
+PREFIX="$1"
+export PATH=$PREFIX/bin:$PATH
+
+: ${CORES:=4}
+: ${ARCHS:=${TOOLCHAIN_ARCHS-i686 x86_64 armv7 aarch64}}
+
+cd mingw-w64/mingw-w64-libraries/winpthreads
+for arch in $ARCHS; do
+    mkdir -p build-$arch
+    cd build-$arch
+    ../configure --host=$arch-w64-mingw32 --prefix=$PREFIX/$arch-w64-mingw32 \
+        CC=$arch-w64-mingw32-clang AR=llvm-ar RANLIB=llvm-ranlib DLLTOOL=llvm-dlltool
+    make -j$CORES
+    make install
+    cd ..
+done