diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6be1ac7f..bfb92b99 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -82,6 +82,7 @@ jobs:
             bash: msys64
           - os: windows-2025
             bash: cygwin
+          - os: windows-11-arm
           - os: windows-2022
             tool: major.minor.patch
           - os: windows-2022
@@ -139,7 +140,7 @@ jobs:
           if [[ "$(cargo binstall -V)" != "$(jq -r '.latest.version' manifests/cargo-binstall.json)" ]]; then
             exit 1
           fi
-        if: matrix.bash != 'cygwin'
+        if: matrix.bash != 'cygwin' && matrix.os != 'windows-11-arm'
 
   test-container:
     strategy:
diff --git a/main.sh b/main.sh
index 9b4c4296..62c88004 100755
--- a/main.sh
+++ b/main.sh
@@ -538,7 +538,10 @@ case "$(uname -m)" in
   # https://github.com/actions/runner/blob/v2.321.0/.github/workflows/build.yml#L21
   # https://docs.github.com/en/actions/hosting-your-own-runners/about-self-hosted-runners#supported-architectures-and-operating-systems-for-self-hosted-runners
   # So we can assume x86_64 unless it is AArch64 or Arm.
-  *) host_arch=x86_64 ;;
+  *)
+    # TODO: uname -m on windows-11-arm returns "x86_64"
+    host_arch=x86_64
+    ;;
 esac
 info "host platform: ${host_arch}_${host_os}"
 
diff --git a/tools/ci/tool-list.sh b/tools/ci/tool-list.sh
index 8d951014..1913a02d 100755
--- a/tools/ci/tool-list.sh
+++ b/tools/ci/tool-list.sh
@@ -124,7 +124,10 @@ esac
 case "$(uname -m)" in
   aarch64 | arm64) host_arch=aarch64 ;;
   xscale | arm | armv*l) bail "32-bit Arm runner is not supported yet by this action; if you need support for this platform, please submit an issue at <https://github.com/taiki-e/install-action>" ;;
-  *) host_arch=x86_64 ;;
+  *)
+    # TODO: uname -m on windows-11-arm returns "x86_64"
+    host_arch=x86_64
+    ;;
 esac
 
 tools=()