diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 7a701ef68508..a01c5d4d5b88 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -53,6 +53,35 @@ jobs:
       - name: Test
         run: bin/ci build
 
+  test_llvm:
+    env:
+      ARCH: x86_64
+      ARCH_CMD: linux64
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - llvm_version: 13.0.0
+          llvm_url: https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/clang+llvm-13.0.0-x86_64-linux-gnu-ubuntu-20.04.tar.xz
+          base_image: ubuntu-20.04
+    runs-on: ${{ matrix.base_image }}
+    name: "Test LLVM ${{ matrix.llvm_version }} (${{ matrix.base_image }})"
+    steps:
+      - name: Download Crystal source
+        uses: actions/checkout@v2
+
+      - name: Prepare System
+        run: bin/ci prepare_system
+
+      - name: Prepare Build
+        run: bin/ci prepare_build
+
+      - name: Install LLVM ${{ matrix.llvm_version }}
+        run: mkdir -p llvm && curl -L ${{ matrix.llvm_url }} > llvm.tar.xz && tar x --xz -C llvm --strip-components=1 -f llvm.tar.xz
+
+      - name: Test
+        run: bin/ci with_build_env "make clean deps compiler_spec crystal std_spec LLVM_CONFIG=\$(pwd)/llvm/bin/llvm-config threads=1 verbose=1 junit_output=.junit/spec.xml"
+
   test_preview_mt:
     env:
       ARCH: x86_64
diff --git a/.github/workflows/win.yml b/.github/workflows/win.yml
index 2dd9cc3567c8..a88ac8a76d18 100644
--- a/.github/workflows/win.yml
+++ b/.github/workflows/win.yml
@@ -246,12 +246,12 @@ jobs:
         uses: actions/cache@v2
         with:
           path: llvm
-          key: llvm-libs-10.0.0
+          key: llvm-libs-13.0.0
       - name: Download LLVM
         if: steps.cache-llvm.outputs.cache-hit != 'true'
         run: |
-          iwr https://github.com/llvm/llvm-project/releases/download/llvmorg-10.0.0/llvm-10.0.0.src.tar.xz -OutFile llvm.tar.xz
-          (Get-FileHash -Algorithm SHA256 .\llvm.tar.xz).hash -eq "df83a44b3a9a71029049ec101fb0077ecbbdf5fe41e395215025779099a98fdf"
+          iwr https://github.com/llvm/llvm-project/releases/download/llvmorg-13.0.0/llvm-13.0.0.src.tar.xz -OutFile llvm.tar.xz
+          (Get-FileHash -Algorithm SHA256 .\llvm.tar.xz).hash -eq "408d11708643ea826f519ff79761fcdfc12d641a2510229eec459e72f8163020"
           7z x llvm.tar.xz
           7z x llvm.tar
           mv llvm-* llvm-src
diff --git a/src/socket/addrinfo.cr b/src/socket/addrinfo.cr
index 9163d94d0260..9163b6c9d617 100644
--- a/src/socket/addrinfo.cr
+++ b/src/socket/addrinfo.cr
@@ -66,7 +66,7 @@ class Socket
               if value.is_a?(Socket::ConnectError)
                 raise Socket::ConnectError.from_os_error("Error connecting to '#{domain}:#{service}'", value.os_error)
               else
-                {% if flag?(:win32) %}
+                {% if flag?(:win32) && compare_versions(Crystal::LLVM_VERSION, "13.0.0") < 0 %}
                   # FIXME: Workardound for https://github.com/crystal-lang/crystal/issues/11047
                   array = StaticArray(UInt8, 0).new(0)
                 {% end %}