diff --git a/scripts/powershell/common.ps1 b/scripts/powershell/common.ps1
index b4df2f7..9c6c5a1 100644
--- a/scripts/powershell/common.ps1
+++ b/scripts/powershell/common.ps1
@@ -226,3 +226,26 @@ function Test-DirHasFiles {
         return $false
     }
 }
+
+function Activate-RepoVenv {
+    $repoRoot = Get-RepoRoot
+    # If inside a .worktrees directory, use its root to detect a VIRTUAL_ENV
+    $venvBase = $repoRoot
+    if ($repoRoot -match ".worktrees") {
+        $venvBase = $repoRoot.Substring(0, $repoRoot.IndexOf(".worktrees"))
+    }
+    $venvPath = Join-Path $venvBase ".venv"
+    $activateScript = Join-Path $venvPath "Scripts/Activate.ps1"
+    if (-not $env:VIRTUAL_ENV) {
+        if (Test-Path $activateScript) {
+            Write-Output "Activating virtual environment at $venvPath"
+            $env:VIRTUAL_ENV = $venvPath
+            & $activateScript
+        } else {
+            Write-Warning ".venv not found at repo root: $venvPath"
+        }
+    }
+}
+
+# auto-activate if not already in a venv
+Activate-RepoVenv