diff --git a/install.ps1 b/install.ps1
index d61a13f..cdc0b8c 100644
--- a/install.ps1
+++ b/install.ps1
@@ -42,7 +42,7 @@ function Ensure-Cargo {
     Write-Info "cargo not found; installing Rust toolchain with winget/rustup"
     winget install --id Rustlang.Rustup -e --accept-package-agreements --accept-source-agreements
     $cargoBin = Join-Path $HOME ".cargo\bin"
-    if (Test-Path $cargoBin) {
+    if ((Test-Path $cargoBin) -and -not (PathList-Contains $env:Path $cargoBin)) {
         $env:Path = "$cargoBin;$env:Path"
     }
     if (-not (Get-Command cargo -ErrorAction SilentlyContinue)) {
diff --git a/tests/release_scripts.rs b/tests/release_scripts.rs
index edc9e50..5f0f727 100644
--- a/tests/release_scripts.rs
+++ b/tests/release_scripts.rs
@@ -213,6 +213,8 @@ fn windows_installer_bootstraps_rust_for_source_fallback_like_unix() {
     assert!(ps1.contains("cargo not found; installing Rust toolchain with winget/rustup"));
     assert!(ps1.contains("winget install --id Rustlang.Rustup"));
     assert!(ps1.contains("--accept-package-agreements --accept-source-agreements"));
+    assert!(ps1.contains("PathList-Contains $env:Path $cargoBin"));
+    assert!(ps1.contains("$env:Path = \"$cargoBin;$env:Path\""));
     assert!(ps1.contains("Ensure-Cargo"));
     assert!(!ps1.contains("Require-Command cargo"));
 }