diff --git a/scripts/install.ps1 b/scripts/install.ps1
index 1f6c12593038..9fc2fa6fb33e 100644
--- a/scripts/install.ps1
+++ b/scripts/install.ps1
@@ -1538,7 +1538,8 @@ function Install-OpenClawFromGit {
             Write-Host "[!] pnpm install failed for the Git checkout" -ForegroundColor Red
             return $false
         }
-        if (-not (& $pnpmCommand ui:build)) {
+        & $pnpmCommand ui:build
+        if ($LASTEXITCODE -ne 0) {
             Write-Host "[!] UI build failed; continuing (CLI may still work)" -ForegroundColor Yellow
         }
         $env:NODE_OPTIONS = Resolve-NodeOptionsWithMinOldSpace -NodeOptions $prevNodeOptions -MinOldSpaceMb 8192
diff --git a/test/scripts/install-ps1.test.ts b/test/scripts/install-ps1.test.ts
index 45584ac8bab1..302471ebc030 100644
--- a/test/scripts/install-ps1.test.ts
+++ b/test/scripts/install-ps1.test.ts
@@ -935,6 +935,8 @@ describe("install.ps1 failure handling", () => {
     expect(gitInstallBody).toContain(
       "$env:NODE_OPTIONS = Resolve-NodeOptionsWithMinOldSpace -NodeOptions $prevNodeOptions -MinOldSpaceMb 8192",
     );
+    expect(gitInstallBody).toMatch(/& \$pnpmCommand ui:build\s+if \(\$LASTEXITCODE -ne 0\)/);
+    expect(gitInstallBody).not.toContain("if (-not (& $pnpmCommand ui:build))");
     expect(nodeOptionsBody).toContain("--max-old-space-size=$MinOldSpaceMb");
     expect(nodeOptionsBody).toContain("[Math]::Max");
     expect(gitInstallBody).toContain("& $pnpmCommand build");