diff --git a/src/apm_cli/core/script_runner.py b/src/apm_cli/core/script_runner.py
index ec3d09a20..f8243c9b3 100644
--- a/src/apm_cli/core/script_runner.py
+++ b/src/apm_cli/core/script_runner.py
@@ -73,7 +73,7 @@ def run_script(self, script_name: str, params: Dict[str, str]) -> bool:
         if discovered_prompt:
             # Print discovery message early to allow E2E tests to validate
             # This message appears before runtime detection, which may fail in test environments
-            print(f"[i] Auto-discovered: {discovered_prompt}")
+            print(f"[i] Auto-discovered: {discovered_prompt.as_posix()}")
 
             # Detect runtime and generate command
             runtime = self._detect_installed_runtime()
diff --git a/src/apm_cli/output/script_formatters.py b/src/apm_cli/output/script_formatters.py
index 12f30b059..779606984 100644
--- a/src/apm_cli/output/script_formatters.py
+++ b/src/apm_cli/output/script_formatters.py
@@ -321,7 +321,7 @@ def format_auto_discovery_message(self, script_name: str, prompt_file: Path, run
             try:
                 text = Text()
                 text.append("[i] Auto-discovered: ", style="cyan")
-                text.append(str(prompt_file), style="bold white")
+                text.append(prompt_file.as_posix(), style="bold white")
                 text.append(f" (runtime: {runtime})", style="dim")
                 
                 with self.console.capture() as capture:
@@ -329,9 +329,9 @@ def format_auto_discovery_message(self, script_name: str, prompt_file: Path, run
                 return capture.get().rstrip('\n')
             except Exception:
                 # Fallback to simple formatting
-                return f"[i] Auto-discovered: {prompt_file} (runtime: {runtime})"
+                return f"[i] Auto-discovered: {prompt_file.as_posix()} (runtime: {runtime})"
         else:
-            return f"[i] Auto-discovered: {prompt_file} (runtime: {runtime})"
+            return f"[i] Auto-discovered: {prompt_file.as_posix()} (runtime: {runtime})"
     
     def _styled(self, text: str, style: str) -> str:
         """Apply styling to text with rich fallback."""