diff --git a/.github/workflows/win.yml b/.github/workflows/win.yml
index e06a0ef88f03..79ea27e59c74 100644
--- a/.github/workflows/win.yml
+++ b/.github/workflows/win.yml
@@ -310,7 +310,7 @@ jobs:
         if: steps.cache-llvm.outputs.cache-hit != 'true'
         working-directory: ./llvm-src
         run: |
-          cmake . -Thost=x64 -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_USE_CRT_RELEASE=MT -DBUILD_SHARED_LIBS=OFF -DCMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH=OFF
+          cmake . -Thost=x64 -DLLVM_TARGETS_TO_BUILD="X86;AArch64" -DLLVM_USE_CRT_RELEASE=MT -DBUILD_SHARED_LIBS=OFF -DCMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH=OFF
           cmake --build . --config Release
       - name: Gather LLVM
         if: steps.cache-llvm.outputs.cache-hit != 'true'
diff --git a/src/compiler/crystal/compiler.cr b/src/compiler/crystal/compiler.cr
index 147a11038cb0..bfa36f9586e9 100644
--- a/src/compiler/crystal/compiler.cr
+++ b/src/compiler/crystal/compiler.cr
@@ -341,8 +341,8 @@ module Crystal
         {% if flag?(:msvc) %}
           if msvc_path = Crystal::System::VisualStudio.find_latest_msvc_path
             if win_sdk_libpath = Crystal::System::WindowsSDK.find_win10_sdk_libpath
-              host_bits = {{ flag?(:bits64) ? "x64" : "x86" }}
-              target_bits = program.has_flag?("bits64") ? "x64" : "x86"
+              host_bits = {{ flag?(:aarch64) ? "ARM64" : flag?(:bits64) ? "x64" : "x86" }}
+              target_bits = program.has_flag?("aarch64") ? "arm64" : program.has_flag?("bits64") ? "x64" : "x86"
 
               # MSVC build tools and Windows SDK found; recreate `LIB` environment variable
               # that is normally expected on the MSVC developer command prompt
@@ -352,6 +352,8 @@ module Crystal
               link_args << Process.quote_windows("/LIBPATH:#{win_sdk_libpath.join("um", target_bits)}")
 
               # use exact path for compiler instead of relying on `PATH`
+              # (letter case shouldn't matter in most cases but being exact doesn't hurt here)
+              target_bits = target_bits.sub("arm", "ARM")
               cl = Process.quote_windows(msvc_path.join("bin", "Host#{host_bits}", target_bits, "cl.exe").to_s)
             end
           end