diff --git a/.github/workflows/multibuild.yml b/.github/workflows/multibuild.yml
index ac69cd89..086c86fb 100644
--- a/.github/workflows/multibuild.yml
+++ b/.github/workflows/multibuild.yml
@@ -29,6 +29,18 @@ jobs:
             PLAT: arm64
             INTERFACE64: ''
             platform: [x64]
+          - os: ubuntu-latest
+            PLAT: x86_64
+            INTERFACE64: '1'
+            MB_ML_LIBC: musllinux
+            MB_ML_VER: _1_1
+            platform: [x64]
+          - os: ubuntu-latest
+            PLAT: x86_64
+            INTERFACE64: ''
+            MB_ML_LIBC: musllinux
+            MB_ML_VER: _1_1
+            platform: [x64]
         exclude:
           - os: macos-latest
             PLAT: i686
@@ -44,6 +56,7 @@ jobs:
       MACOSX_DEPLOYMENT_TARGET: 10.9
       MB_PYTHON_VERSION: ${{ matrix.python-version }}
       TRAVIS_PYTHON_VERSION: ${{ matrix.python-version }}
+      MB_ML_LIBC: ${{ matrix.MB_ML_LIBC }}
       MB_ML_VER: ${{ matrix.MB_ML_VER }}
       INTERFACE64: ${{ matrix.INTERFACE64 }}
       BUILD_DIR: ${{ github.workspace }}
diff --git a/.gitmodules b/.gitmodules
index ae67f995..9a0ddc0f 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -3,7 +3,7 @@
 	url = https://github.com/xianyi/OpenBLAS.git
 [submodule "multibuild"]
 	path = multibuild
-	url = https://github.com/matthew-brett/multibuild.git
+	url = https://github.com/multi-build/multibuild.git
 [submodule "gfortran-install"]
 	path = gfortran-install
 	url = https://github.com/MacPython/gfortran-install.git
diff --git a/.travis.yml b/.travis.yml
index 6baff477..62128da0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -23,6 +23,21 @@ services: docker
 
 matrix:
   include:
+    - os: linux
+      arch: arm64
+      env:
+        - PLAT=aarch64
+        - MB_ML_VER=_1_1
+        - MB_ML_LIBC=musllinux
+        - DOCKER_TEST_IMAGE=multibuild/xenial_{PLAT}
+    - os: linux
+      arch: arm64
+      env:
+        - PLAT=aarch64
+        - INTERFACE64=1
+        - MB_ML_VER=_1_1
+        - MB_ML_LIBC=musllinux
+        - DOCKER_TEST_IMAGE=multibuild/xenial_{PLAT}
     - os: linux
       arch: arm64
       env:
diff --git a/multibuild b/multibuild
index 7684e52b..4b6eb06a 160000
--- a/multibuild
+++ b/multibuild
@@ -1 +1 @@
-Subproject commit 7684e52bcb023d511c4f17b638d497203f218a68
+Subproject commit 4b6eb06af94d39b04a4136bb6781bd0100816c7d
diff --git a/travis-ci/build_steps.sh b/travis-ci/build_steps.sh
index 761370ac..6b13ca37 100644
--- a/travis-ci/build_steps.sh
+++ b/travis-ci/build_steps.sh
@@ -26,6 +26,33 @@ function before_build {
     fi
 }
 
+function get_plat_tag {
+    # Copied from gfortran-install/gfortran_utils.sh, modified for MB_ML_LIBC
+
+    # Modify fat architecture tags on macOS to reflect compiled architecture
+    # For non-darwin, report manylinux version
+    local plat=$1
+    local mb_ml_ver=${MB_ML_VER:-1}
+    local mb_ml_libc=${MB_ML_LIBC:-manylinux}
+    case $plat in
+        i686|x86_64|arm64|universal2|intel|aarch64|s390x|ppc64le) ;;
+        *) echo Did not recognize plat $plat; return 1 ;;
+    esac
+    local uname=${2:-$(uname)}
+    if [ "$uname" != "Darwin" ]; then
+        if [ "$plat" == "intel" ]; then
+            echo plat=intel not allowed for Manylinux
+            return 1
+        fi
+        echo "${mb_ml_libc}${mb_ml_ver}_${plat}"
+        return
+    fi
+    # macOS 32-bit arch is i386
+    [ "$plat" == "i686" ] && plat="i386"
+    local target=$(echo $MACOSX_DEPLOYMENT_TARGET | tr .- _)
+    echo "macosx_${target}_${plat}"
+}
+
 function build_lib {
     # OSX or manylinux build
     #
@@ -48,7 +75,8 @@ function build_lib {
         return
     fi
     # Manylinux wrapper
-    local docker_image=quay.io/pypa/manylinux${manylinux}_${plat}
+    local libc=${MB_ML_LIBC:-manylinux}
+    local docker_image=quay.io/pypa/${libc}${manylinux}_${plat}
     docker pull $docker_image
     # Docker sources this script, and runs `do_build_lib`
     docker run --rm \
@@ -57,6 +85,7 @@ function build_lib {
         -e INTERFACE64="${interface64}" \
         -e PYTHON_VERSION="$MB_PYTHON_VERSION" \
         -e MB_ML_VER=${manylinux} \
+        -e MB_ML_LIBC=${libc} \
         -v $PWD:/io \
         $docker_image /io/travis-ci/docker_build_wrap.sh
 }
@@ -137,7 +166,7 @@ function do_build_lib {
     && make PREFIX=$BUILD_PREFIX $interface64_flags install )
     stop_spinner
     local version=$(cd OpenBLAS && git describe --tags --abbrev=8)
-    local plat_tag=$(get_distutils_platform_ex $plat)
+    local plat_tag=$(get_plat_tag $plat)
     local suff=""
     [ -n "$suffix" ] && suff="-$suffix"
     if [ "$interface64" = "1" ]; then