diff --git a/action.yml b/action.yml
index fc7f4f8..6c490d2 100644
--- a/action.yml
+++ b/action.yml
@@ -9,13 +9,10 @@ runs:
   using: "composite"
   steps:
     - name: Install on Mac/Linux/Windows
-      run: |
-        pip3 install wheel setuptools
-        pip3 install ninja --upgrade
+      run: bash $GITHUB_ACTION_PATH/install-ninja.sh
       shell: bash
-    - name: Fix path on Linux
-      run: |
-        echo "/home/runner/.local/bin" >> $GITHUB_PATH
+    - name: Fix path
+      run: echo "$HOME/.local/bin" >> $GITHUB_PATH
       shell: bash
     - name: Fill in output variable
       id: output_version
diff --git a/checksums.txt b/checksums.txt
new file mode 100644
index 0000000..9baa188
--- /dev/null
+++ b/checksums.txt
@@ -0,0 +1,5 @@
+daa94231f55bf32a46b1b45e3a0dc767f73483a681d3277923833df9ac4f12532d67e9aca2f45768f31c8b3b8e63149d69867cb0a0e6c48683f197bf2634d681  ninja-linux-aarch64.zip
+a6d4c8410cc7cd0eced47518b8deca90af9e6f9b1e9fba992bcc5bc92645d07e20bd005a59c90c4c24cded68a4f2178f3a2043707e578e326881ffdaae073f2f  ninja-linux.zip
+cb271573df79c36a61bf6f63ff7aca7e2e7e3764c1ef0ce8e6f4667dae54326f905061cf56f19aea37625c94eeb96abc8f643b14d0e65da70e2e6cf9d127a52a  ninja-win.zip
+23726030fa0ffd05afef6cf75042ad7518fb954af058f85a8a3fdab4e8d157ef42347b6232d20c1a609e91d9c38ebfd2f1cdc751ca6eb1f87e333cc6971455a5  ninja-mac.zip
+35b9228d91c133eabf8318b0842d6621be7b11ffaa46bfc3cf0cfe9aa5858c2db7b5dc7c475444f0da8cd07b35304e0c61f53cf264f258a6902c74b26438c248  ninja-winarm64.zip
diff --git a/install-ninja.sh b/install-ninja.sh
new file mode 100755
index 0000000..c3ac0c2
--- /dev/null
+++ b/install-ninja.sh
@@ -0,0 +1,39 @@
+#! /bin/bash
+
+echo "Runner $RUNNER_OS $RUNNER_ARCH"
+
+wget=wget
+if [ "$RUNNER_OS" == "Windows" ]; then
+    if [ "$RUNNER_ARCH" == "ARM64" ]; then
+        filename=ninja-winarm64.zip
+    else
+        filename=ninja-win.zip
+    fi
+    wget=C:/msys64/usr/bin/wget.exe
+    checksum=sha512sum
+elif [ "$RUNNER_OS" == "macOS" ]; then
+    filename=ninja-mac.zip
+    checksum="shasum -a 512"
+elif [ "$RUNNER_OS" == "Linux" ]; then
+    if [ "$RUNNER_ARCH" == "ARM64" ]; then
+        filename=ninja-linux-aarch64.zip
+    else
+        filename=ninja-linux.zip
+    fi
+    checksum="sha512sum"
+else
+    echo "$RUNNER_OS not supported"
+    exit 1
+fi
+if ! $wget -q "https://github.com/ninja-build/ninja/releases/download/v1.12.0/$filename" ; then
+    echo "Couldn't download $filename file"
+    exit 2
+fi
+
+cp $GITHUB_ACTION_PATH/checksums.txt .
+if ! $checksum --ignore-missing --check checksums.txt ; then
+    echo "Invalid SHA512 checksum"
+    exit 3
+fi
+mkdir -p "$HOME/.local/bin"
+unzip -d "$HOME/.local/bin" "$filename"