diff --git a/graphify/cli.py b/graphify/cli.py
index 26cce2320b..7932f5c834 100644
--- a/graphify/cli.py
+++ b/graphify/cli.py
@@ -71,7 +71,8 @@
 _HOOK_SOURCE_EXTS = (
     '.py', '.js', '.cjs', '.ts', '.tsx', '.jsx', '.astro', '.vue', '.svelte', '.go',
     '.rs', '.java', '.rb', '.c', '.h', '.cpp', '.hpp', '.cc', '.cs', '.kt',
-    '.swift', '.php', '.scala', '.lua', '.sh', '.md', '.rst', '.txt', '.mdx',
+    '.swift', '.php', '.scala', '.lua', '.ps1', '.psm1', '.psd1',  # #4271: PowerShell sources are graphable too
+    '.sh', '.md', '.rst', '.txt', '.mdx',
 )
 _GEMINI_NUDGE_TEXT = (
     'graphify: knowledge graph at graphify-out/. For focused questions, run '
diff --git a/tests/test_hook_guard.py b/tests/test_hook_guard.py
index e75d4e9d0f..ddfa275483 100644
--- a/tests/test_hook_guard.py
+++ b/tests/test_hook_guard.py
@@ -127,6 +127,10 @@ def test_search_non_dict_tool_input_is_silent(tmp_path, monkeypatch):
     {"file_path": "SRC/APP.PY"},                 # uppercase extension
     {"file_path": "src/a.test.tsx"},             # multi-dot -> .tsx
     {"file_path": "lib/foo.min.js"},             # multi-dot -> .js
+    {"file_path": "scripts/deploy.ps1"},          # #4271: PowerShell sources nudge too
+    {"file_path": "scripts/Module.psm1"},         # #4271
+    {"file_path": "scripts/Module.psd1"},         # #4271
+    {"file_path": "scripts/DEPLOY.PS1"},          # #4271: uppercase extension
     {"file_path": r"src\components\app.py"},     # windows backslashes
     {"pattern": "**/*.py", "path": "src"},       # glob pattern
     {"pattern": "**/*.astro"},