diff --git a/tests/test_check_prerequisites_paths_only.py b/tests/test_check_prerequisites_paths_only.py
index 0675da3113..50317e640f 100644
--- a/tests/test_check_prerequisites_paths_only.py
+++ b/tests/test_check_prerequisites_paths_only.py
@@ -17,7 +17,7 @@
 CHECK_PREREQS_PS = PROJECT_ROOT / "scripts" / "powershell" / "check-prerequisites.ps1"
 
 HAS_PWSH = shutil.which("pwsh") is not None
-_POWERSHELL = shutil.which("powershell.exe") or shutil.which("powershell")
+_POWERSHELL = (shutil.which("powershell.exe") or shutil.which("powershell")) if os.name == "nt" else None
 
 
 def _install_bash_scripts(repo: Path) -> None:
diff --git a/tests/test_setup_plan_feature_json.py b/tests/test_setup_plan_feature_json.py
index 7f44a47923..b1c2332126 100644
--- a/tests/test_setup_plan_feature_json.py
+++ b/tests/test_setup_plan_feature_json.py
@@ -18,7 +18,7 @@
 PLAN_TEMPLATE = PROJECT_ROOT / "templates" / "plan-template.md"
 
 HAS_PWSH = shutil.which("pwsh") is not None
-_POWERSHELL = shutil.which("powershell.exe") or shutil.which("powershell")
+_POWERSHELL = (shutil.which("powershell.exe") or shutil.which("powershell")) if os.name == "nt" else None
 
 
 def _install_bash_scripts(repo: Path) -> None:
diff --git a/tests/test_setup_plan_no_overwrite.py b/tests/test_setup_plan_no_overwrite.py
index 23c4a32335..cc1a741a78 100644
--- a/tests/test_setup_plan_no_overwrite.py
+++ b/tests/test_setup_plan_no_overwrite.py
@@ -18,7 +18,7 @@
 PLAN_TEMPLATE = PROJECT_ROOT / "templates" / "plan-template.md"
 
 HAS_PWSH = shutil.which("pwsh") is not None
-_POWERSHELL = shutil.which("powershell.exe") or shutil.which("powershell")
+_POWERSHELL = (shutil.which("powershell.exe") or shutil.which("powershell")) if os.name == "nt" else None
 
 
 def _install_bash_scripts(repo: Path) -> None:
diff --git a/tests/test_setup_tasks.py b/tests/test_setup_tasks.py
index 233f342664..5b35160a75 100644
--- a/tests/test_setup_tasks.py
+++ b/tests/test_setup_tasks.py
@@ -20,7 +20,7 @@
 TASKS_TEMPLATE = PROJECT_ROOT / "templates" / "tasks-template.md"
  
 HAS_PWSH = shutil.which("pwsh") is not None
-_POWERSHELL = shutil.which("powershell.exe") or shutil.which("powershell")
+_POWERSHELL = (shutil.which("powershell.exe") or shutil.which("powershell")) if os.name == "nt" else None
  
  
 # ---------------------------------------------------------------------------