diff --git a/.github/workflows/test-install.yml b/.github/workflows/test-install.yml
index ea15a74be..d78e9fa0d 100644
--- a/.github/workflows/test-install.yml
+++ b/.github/workflows/test-install.yml
@@ -31,10 +31,9 @@ jobs:
 
     - name: Install
       # Command needs to be wrapped in single quotes so backslashes are preserved for Windows paths
-      run: "'${{ github.workspace }}${{ env.SEP }}main.sh'"
+      run: "'${{ github.workspace }}${{ runner.os == 'Windows' && '\\' || '/' }}main.sh'"
       shell: bash
       env:
-        SEP: ${{ runner.os == 'Windows' && '\' || '/' }}
         VERSION: latest
 
     - name: Verify
diff --git a/README.md b/README.md
index e56f6c0b6..18b45959c 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ For strict security guarantees, it's best practice to [pin](https://docs.github.
 
 ```yaml
 - name: Install Hatch
-  uses: pypa/hatch@05d55c44632b129e63a7f0515803384fbf83fe89
+  uses: pypa/hatch@f4b68bbda7951a6654d3c9f9bb5e92fe9f68a14f
 ```
 
 ## Options
@@ -30,6 +30,7 @@ Name | Default | Description
 
 It's possible to use the [install script](https://github.com/pypa/hatch/blob/install/main.sh) outside of GitHub Actions assuming you set up your environment as follows:
 
+- Set every [option](#options) to an environment variable with uppercasing and replacing hyphens with underscores.
 - Set the `RUNNER_TOOL_CACHE` environment variable to the directory where you want to install Hatch.
 - Set the `GITHUB_PATH` environment variable to a file that is writable which will contain the directory where Hatch is installed (usually `$RUNNER_TOOL_CACHE/.hatch`).
 - Set the `RUNNER_OS` environment variable to the current platform using one of the following values:
@@ -39,5 +40,4 @@ It's possible to use the [install script](https://github.com/pypa/hatch/blob/ins
 - Set the `RUNNER_ARCH` environment variable to the current architecture using one of the following values:
     - `X64`
     - `ARM64`
-- Set the `SEP` environment variable to the current platform's path separator (`/` for Linux/macOS, `\` for Windows).
 - Install [pipx](https://github.com/pypa/pipx) as a fallback installation method for when there is no [standalone binary](https://hatch.pypa.io/latest/install/#standalone-binaries) available.
diff --git a/action.yml b/action.yml
index c8dbb606c..8944bf994 100644
--- a/action.yml
+++ b/action.yml
@@ -14,8 +14,7 @@ runs:
   steps:
   - name: Install and configure Hatch
     # Command needs to be wrapped in single quotes so backslashes are preserved for Windows paths
-    run: "'${{ github.action_path }}${{ env.SEP }}main.sh'"
+    run: "'${{ github.action_path }}${{ runner.os == 'Windows' && '\\' || '/' }}main.sh'"
     shell: bash
     env:
-      SEP: ${{ runner.os == 'Windows' && '\' || '/' }}
       VERSION: ${{ inputs.version }}
diff --git a/main.sh b/main.sh
index cdd50e1d1..132e31f82 100755
--- a/main.sh
+++ b/main.sh
@@ -2,10 +2,16 @@
 set -euo pipefail
 IFS=$'\n\t'
 
-INSTALL_PATH="${RUNNER_TOOL_CACHE}${SEP}.hatch"
 PURPLE="\033[1;35m"
 RESET="\033[0m"
 
+if [[ "${RUNNER_OS}" == "Windows" ]]; then
+  SEP="\\"
+else
+  SEP="/"
+fi
+INSTALL_PATH="${RUNNER_TOOL_CACHE}${SEP}.hatch"
+
 install_hatch() {
   mkdir -p "${INSTALL_PATH}"
   archive="${INSTALL_PATH}${SEP}$1"