diff --git a/src/skillspector/cli.py b/src/skillspector/cli.py
index 83e3224..75a5c14 100644
--- a/src/skillspector/cli.py
+++ b/src/skillspector/cli.py
@@ -24,6 +24,7 @@
 import json
 import os
 import shutil
+import sys
 from enum import StrEnum
 from pathlib import Path
 from typing import Annotated
@@ -38,6 +39,26 @@
 
 logger = get_logger(__name__)
 
+
+def _ensure_utf8_streams() -> None:
+    """Reconfigure stdout/stderr to UTF-8 so Unicode report output does not crash.
+
+    On Windows the default console encoding (e.g. cp1252) cannot encode the
+    box-drawing characters and icons used in the terminal report, which raises
+    UnicodeEncodeError. Reconfiguring with errors="replace" makes output robust
+    across platforms without crashing.
+    """
+    for stream in (sys.stdout, sys.stderr):
+        reconfigure = getattr(stream, "reconfigure", None)
+        if reconfigure is not None:
+            try:
+                reconfigure(encoding="utf-8", errors="replace")
+            except (ValueError, OSError):
+                logger.debug("Could not reconfigure %s to UTF-8", stream)
+
+
+_ensure_utf8_streams()
+
 app = typer.Typer(
     name="skillspector",
     help="Security scanner for AI agent skills (LangGraph). Detect vulnerabilities before installation.",
diff --git a/src/skillspector/nodes/build_context.py b/src/skillspector/nodes/build_context.py
index 694a048..947ab88 100644
--- a/src/skillspector/nodes/build_context.py
+++ b/src/skillspector/nodes/build_context.py
@@ -87,7 +87,7 @@ def _walk_skill_files(skill_dir: Path) -> list[str]:
             continue
         try:
             rel = item.relative_to(skill_dir)
-            paths.append(str(rel))
+            paths.append(rel.as_posix())
         except ValueError:
             logger.debug("Skipping path (not under skill_dir): %s", item)
             continue
diff --git a/tests/nodes/analyzers/test_semantic_developer_intent.py b/tests/nodes/analyzers/test_semantic_developer_intent.py
index 0ddc704..097b9b1 100644
--- a/tests/nodes/analyzers/test_semantic_developer_intent.py
+++ b/tests/nodes/analyzers/test_semantic_developer_intent.py
@@ -342,7 +342,7 @@ def _build_file_cache(skill_dir: Path) -> dict[str, str]:
     for item in sorted(skill_dir.rglob("*")):
         if not item.is_file():
             continue
-        rel = str(item.relative_to(skill_dir))
+        rel = item.relative_to(skill_dir).as_posix()
         try:
             cache[rel] = item.read_text(encoding="utf-8", errors="replace")
         except OSError:
diff --git a/tests/nodes/analyzers/test_semantic_security_discovery.py b/tests/nodes/analyzers/test_semantic_security_discovery.py
index 85209f6..4883fec 100644
--- a/tests/nodes/analyzers/test_semantic_security_discovery.py
+++ b/tests/nodes/analyzers/test_semantic_security_discovery.py
@@ -317,7 +317,7 @@ def _build_file_cache(skill_dir: Path) -> dict[str, str]:
     for item in sorted(skill_dir.rglob("*")):
         if not item.is_file():
             continue
-        rel = str(item.relative_to(skill_dir))
+        rel = item.relative_to(skill_dir).as_posix()
         try:
             cache[rel] = item.read_text(encoding="utf-8", errors="replace")
         except OSError:
diff --git a/tests/nodes/test_semantic_quality_policy.py b/tests/nodes/test_semantic_quality_policy.py
index f80960b..7cce237 100644
--- a/tests/nodes/test_semantic_quality_policy.py
+++ b/tests/nodes/test_semantic_quality_policy.py
@@ -289,7 +289,7 @@ def _build_file_cache(skill_dir: Path) -> dict[str, str]:
     for item in sorted(skill_dir.rglob("*")):
         if not item.is_file():
             continue
-        rel = str(item.relative_to(skill_dir))
+        rel = item.relative_to(skill_dir).as_posix()
         try:
             cache[rel] = item.read_text(encoding="utf-8", errors="replace")
         except OSError:
diff --git a/tests/test_mcp_least_privilege.py b/tests/test_mcp_least_privilege.py
index 9e7852e..d9a045f 100644
--- a/tests/test_mcp_least_privilege.py
+++ b/tests/test_mcp_least_privilege.py
@@ -98,7 +98,7 @@ def _make_state(fixture_name: str) -> dict:
             continue
         if item.name.startswith(".") and not item.name.startswith(".claude"):
             continue
-        rel = str(item.relative_to(fixture_dir))
+        rel = item.relative_to(fixture_dir).as_posix()
         components.append(rel)
     components.sort()
 
diff --git a/tests/test_mcp_tool_poisoning.py b/tests/test_mcp_tool_poisoning.py
index 7d5b524..9e3e25f 100644
--- a/tests/test_mcp_tool_poisoning.py
+++ b/tests/test_mcp_tool_poisoning.py
@@ -121,7 +121,7 @@ def _make_state(
             continue
         if item.name.startswith(".") and not item.name.startswith(".claude"):
             continue
-        rel = str(item.relative_to(fixture_dir))
+        rel = item.relative_to(fixture_dir).as_posix()
         components.append(rel)
     components.sort()