diff --git a/README.md b/README.md
index aa2cc6d..cecb4e5 100644
--- a/README.md
+++ b/README.md
@@ -59,7 +59,7 @@ For legacy DDKBuild projects:
 ```yaml
 - name: build driver
   shell: cmd
-  run: call "${{ steps.wdk7.outputs.ddkbuild-cmd }}" -WIN7A64 free src
+  run: call ddkbuild.cmd -WIN7A64 free src
 ```
 
 Use `root` to point at a preinstalled WDK7 tree, or `download-url` to provide
diff --git a/dist/index.js b/dist/index.js
index 543b4d6..84bfcde 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -29172,6 +29172,7 @@ function publishWdk7(root, source, cacheHit, sdk) {
   exportVariable("WDK7_DDKBUILD_CMD", ddkbuildCmd());
   exportVariable("WDK7_CMAKE_GENERATOR", cmakeGenerator);
   addPath(host);
+  addPath(actionRoot());
   setOutput("found", "true");
   setOutput("root", resolvedRoot);
   setOutput("source", source);
diff --git a/scripts/test-e2e.ps1 b/scripts/test-e2e.ps1
index 7dd24b5..e3c004a 100644
--- a/scripts/test-e2e.ps1
+++ b/scripts/test-e2e.ps1
@@ -32,6 +32,27 @@ function Assert-ExistingPath {
     }
 }
 
+<#
+.SYNOPSIS
+Ensures a command is available through PATH before the e2e script uses it.
+
+.DESCRIPTION
+The action adds bundled helper commands to PATH for downstream steps. Checking
+command resolution directly protects the user-facing contract that legacy
+projects can call ddkbuild.cmd without referencing an action output.
+#>
+function Assert-CommandAvailable {
+    param(
+        [string]$CommandName
+    )
+
+    # Get-Command tests the same PATH-based resolution that a later cmd.exe call
+    # relies on when it invokes the bundled batch wrapper.
+    if ($null -eq (Get-Command $CommandName -ErrorAction SilentlyContinue)) {
+        throw "$CommandName is not available on PATH."
+    }
+}
+
 <#
 .SYNOPSIS
 Runs a command and exits with the command's status when it fails.
@@ -198,7 +219,7 @@ function Build-DdkbuildTarget {
         # expects normal cmd call semantics. The source path stays relative
         # because legacy ddkbuild path handling is more reliable with repo-local
         # target directories than with absolute workflow paths.
-        Invoke-Checked "cmd" @("/s", "/c", "call ""$env:WDK7_DDKBUILD_CMD"" $target free ""$source""")
+        Invoke-Checked "cmd" @("/s", "/c", "call ddkbuild.cmd $target free ""$source""")
     }
 
     $sysFiles = @(Get-ChildItem -Path $sourcePath -Recurse -Filter e2e_ddkbuild.sys)
@@ -214,7 +235,7 @@ function Build-DdkbuildTarget {
 
 Assert-ExistingPath $env:WDK7_ROOT "WDK7_ROOT is not set or does not exist."
 Assert-ExistingPath $env:WDK7_CMAKE_TOOLCHAIN_FILE "WDK7_CMAKE_TOOLCHAIN_FILE is not set or does not exist."
-Assert-ExistingPath $env:WDK7_DDKBUILD_CMD "WDK7_DDKBUILD_CMD is not set or does not exist."
+Assert-CommandAvailable "ddkbuild.cmd"
 
 if ([string]::IsNullOrWhiteSpace($env:WDK7_CMAKE_GENERATOR)) {
     throw "WDK7_CMAKE_GENERATOR is not set."
diff --git a/src/action.ts b/src/action.ts
index 3ce7b55..a17d6ee 100644
--- a/src/action.ts
+++ b/src/action.ts
@@ -222,6 +222,10 @@ export function publishWdk7(root: string, source: string, cacheHit: boolean, sdk
   // invoke NMake and rc.exe after the action step completes.
   core.addPath(host);
 
+  // The action root is added so legacy projects can run ddkbuild.cmd directly
+  // without reaching through a step output for the bundled wrapper path.
+  core.addPath(actionRoot());
+
   core.setOutput("found", "true");
   core.setOutput("root", resolvedRoot);
   core.setOutput("source", source);