diff --git a/.github/actions/merge-windows/action.yml b/.github/actions/merge-windows/action.yml
index adfdd3d4c76..cec5f458491 100644
--- a/.github/actions/merge-windows/action.yml
+++ b/.github/actions/merge-windows/action.yml
@@ -31,7 +31,7 @@ runs:
         $conf32 = "`r`n""i[3-6]86-.*-windows-msvc"":" + $conf32.Substring($conf32.IndexOf("`r`ndefault:") + 10)
         $conf32 = $conf32.Substring(0, $conf32.IndexOf("`r`n};`r`n") + 6)
         $conf32 = $conf32.Replace('%%ldcbinarypath%%/../lib', '%%ldcbinarypath%%/../lib32')
-        Add-Content etc\ldc2.conf $conf32
+        Add-Content etc\ldc2.conf $conf32 -NoNewline
         cat etc\ldc2.conf
 
     - name: Generate hello.d
@@ -63,6 +63,49 @@ runs:
         set PATH=%CD%\ldc2-multilib\lib32;%PATH%
         ldc2-multilib\bin\ldc2 -link-defaultlib-shared -m32 -run hello.d || exit /b
 
+    # preliminary arm64 cross-compilation support
+    - name: Install ninja v1.12.1
+      uses: Ahajha/gha-setup-ninja@69595b0cf872acdad8ce599142fbdc88724b9a2b
+    - name: Set VSDIR env variable
+      shell: bash
+      run: echo "VSDIR=$(vswhere -latest -property installationPath)" >> $GITHUB_ENV
+    - name: Cross-compile arm64 libraries
+      shell: cmd
+      run: |
+        echo on
+        call "%VSDIR%\Common7\Tools\VsDevCmd.bat" -arch=arm64 -host_arch=x64 || exit /b
+        echo on
+        ldc2-multilib\bin\ldc-build-runtime --ninja ^
+          --buildDir=build-libs-arm64 ^
+          --dFlags=-mtriple=aarch64-windows-msvc ^
+          "--ldcSrcDir=%CD%" ^
+          BUILD_LTO_LIBS=ON
+    - name: Copy arm64 libraries
+      shell: bash
+      run: |
+        set -eux
+        cp -R build-libs-arm64/lib ldc2-multilib/libarm64
+        rm ldc2-multilib/libarm64/*.{exp,ilk}
+        rm ldc2-multilib/libarm64/{druntime,phobos2}-ldc-shared.pdb
+    - name: Add arm64 section to ldc2.conf
+      shell: pwsh
+      run: |
+        cd ldc2-multilib
+        $conf64 = cat etc\ldc2.conf -Raw
+        $conf64 = "`r`n""(aarch|arm)64-.*-windows-msvc"":" + $conf64.Substring($conf64.IndexOf("`r`ndefault:") + 10)
+        $conf64 = $conf64.Substring(0, $conf64.IndexOf("`r`n};`r`n") + 6)
+        $conf64 = $conf64.Replace('%%ldcbinarypath%%/../lib64', '%%ldcbinarypath%%/../libarm64')
+        Add-Content etc\ldc2.conf $conf64 -NoNewline
+        cat etc\ldc2.conf
+    - name: Run arm64 hello-world cross-compilation smoke tests
+      shell: cmd
+      run: |
+        echo on
+        call "%VSDIR%\Common7\Tools\VsDevCmd.bat" -arch=arm64 -host_arch=x64 || exit /b
+        echo on
+        ldc2-multilib\bin\ldc2 -mtriple=aarch64-windows-msvc hello.d || exit /b
+        ldc2-multilib\bin\ldc2 -mtriple=aarch64-windows-msvc -link-defaultlib-shared hello.d || exit /b
+
     - name: Pack multilib package
       shell: bash
       run: |
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 7abdcaa0500..cf26b34f9ee 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -317,11 +317,14 @@ jobs:
 
   merge-windows:
     name: Windows multilib
-    runs-on: windows-latest
+    runs-on: windows-2022
     timeout-minutes: 30
     needs: build-native
     steps:
       - uses: actions/checkout@v4
+        with:
+          submodules: true
+          fetch-depth: 50
       - name: Merge x64 & x86 packages to multilib one & build installer
         uses: ./.github/actions/merge-windows
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index fb6b67625da..f5e0a2a93fb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,7 @@
 #### Platform support
 - Supports LLVM 15 - 19.
 - Initial compiler and runtime support for ppc64 and ppc64le systems that use IEEE 754R 128-bit floating-point as the default 128-bit floating-point format. (#4833)
-- Added support for building for Windows on ARM64. Use option '-march=arm64' to compile, 'ldc-build-runtime.exe --dFlags -march=arm64' to build the runtime libraries. (#4835)
+- Initial support for Windows on ARM64. The prebuilt Windows multilib package/installer bundles prebuilt arm64 druntime and Phobos; cross-compiling works out of the box via `-mtriple=aarch64-windows-msvc`, but you currently need to set up a suited MSVC arm64 build environment before yourself (e.g., by running `vsdevcmd.bat -arch=arm64 -host_arch=x64`). There's no bundled libcurl either yet. (#4835, #4846)
 
 #### Bug fixes
 - Building multi-file D applications with control-flow protection will no longer cause LDC to throw an internal compiler error. (#4828)
diff --git a/packaging/windows_installer.iss b/packaging/windows_installer.iss
index 69f50fe1bcf..c1dc469a544 100644
--- a/packaging/windows_installer.iss
+++ b/packaging/windows_installer.iss
@@ -29,14 +29,16 @@ SolidCompression=yes
 Name: "english"; MessagesFile: "compiler:Default.isl"
 
 [Files]
-Source: "{#LDCDir}\*"; Excludes: "\lib32,\lib64"; DestDir: "{app}"; Components: core; Flags: ignoreversion recursesubdirs
+Source: "{#LDCDir}\*"; Excludes: "\lib32,\lib64,\libarm64"; DestDir: "{app}"; Components: core; Flags: ignoreversion recursesubdirs
 Source: "{#LDCDir}\lib64\*"; DestDir: "{app}\lib64"; Components: lib64; Flags: ignoreversion recursesubdirs
 Source: "{#LDCDir}\lib32\*"; DestDir: "{app}\lib32"; Components: lib32; Flags: ignoreversion recursesubdirs
+Source: "{#LDCDir}\libarm64\*"; DestDir: "{app}\libarm64"; Components: libarm64; Flags: ignoreversion recursesubdirs
 
 [Components]
 Name: core; Description: "Executables, config file and imports"; Types: full compact custom; Flags: fixed
 Name: lib64; Description: "x64 libraries"; Types: full compact
 Name: lib32; Description: "x86 libraries"; Types: full
+Name: libarm64; Description: "arm64 libraries"; Types: full
 
 [Run]
 ; note: not added to PATH for silent installs with /SILENT or /VERYSILENT