diff --git a/src/controllers/document.controller.ts b/src/controllers/document.controller.ts
index e351929..56be8e1 100644
--- a/src/controllers/document.controller.ts
+++ b/src/controllers/document.controller.ts
@@ -389,7 +389,13 @@ export const uploadDocument = async (req: AuthenticatedRequest, res: Response) =
     }
 
     // 2. Upload File to Supabase Storage
-    const filePath = `${user_id}/${Date.now()}_${file.originalname}`;
+    const sanitizeFilename = (name: string) => {
+      const charMap: Record<string, string> = { 'ç': 'c', 'ğ': 'g', 'ı': 'i', 'ö': 'o', 'ş': 's', 'ü': 'u', 'Ç': 'C', 'Ğ': 'G', 'İ': 'I', 'Ö': 'O', 'Ş': 'S', 'Ü': 'U' };
+      const engName = name.replace(/[çğıöşüÇĞİÖŞÜ]/g, m => charMap[m]);
+      return engName.replace(/[^a-zA-Z0-9.\-_]/g, '_');
+    };
+    const safeName = sanitizeFilename(file.originalname);
+    const filePath = `${user_id}/${Date.now()}_${safeName}`;
     const { error: uploadError } = await supabase.storage
       .from('case-documents')
       .upload(filePath, file.buffer, {
diff --git a/src/controllers/template.controller.ts b/src/controllers/template.controller.ts
index 0a07672..8f01b1f 100644
--- a/src/controllers/template.controller.ts
+++ b/src/controllers/template.controller.ts
@@ -29,7 +29,14 @@ export const uploadTemplate = async (req: AuthenticatedRequest, res: Response) =
       console.error('Template Text Extraction Error:', err);
     }
 
-    const storagePath = `templates/${userId}/${Date.now()}_${file.originalname}`;
+    const sanitizeFilename = (name: string) => {
+      const charMap: Record<string, string> = { 'ç': 'c', 'ğ': 'g', 'ı': 'i', 'ö': 'o', 'ş': 's', 'ü': 'u', 'Ç': 'C', 'Ğ': 'G', 'İ': 'I', 'Ö': 'O', 'Ş': 'S', 'Ü': 'U' };
+      const engName = name.replace(/[çğıöşüÇĞİÖŞÜ]/g, m => charMap[m]);
+      return engName.replace(/[^a-zA-Z0-9.\-_]/g, '_');
+    };
+    
+    const safeName = sanitizeFilename(file.originalname);
+    const storagePath = `templates/${userId}/${Date.now()}_${safeName}`;
     const { error: uploadError } = await supabase.storage
       .from('case-documents')
       .upload(storagePath, file.buffer, { contentType: file.mimetype });
diff --git a/test_db.js b/test_db.js
new file mode 100644
index 0000000..f1a7ed5
--- /dev/null
+++ b/test_db.js
@@ -0,0 +1,10 @@
+require('dotenv').config();
+const { createClient } = require('@supabase/supabase-js');
+const supabase = createClient(process.env.SUPABASE_URL, process.env.SUPABASE_SERVICE_ROLE_KEY);
+
+async function run() {
+  const { data, error } = await supabase.from('templates').select('*').limit(1);
+  if (error) console.error('Error:', error.message);
+  else console.log('Success:', data);
+}
+run();
diff --git a/test_upload.js b/test_upload.js
new file mode 100644
index 0000000..8704a0d
--- /dev/null
+++ b/test_upload.js
@@ -0,0 +1,12 @@
+require('dotenv').config();
+const { createClient } = require('@supabase/supabase-js');
+const supabaseUrl = process.env.SUPABASE_URL;
+const supabaseKey = process.env.SUPABASE_SERVICE_ROLE_KEY || process.env.SUPABASE_ANON_KEY;
+const supabase = createClient(supabaseUrl, supabaseKey);
+
+async function run() {
+  const { data, error } = await supabase.storage.from('case-documents').upload('templates/test_user_id/test.txt', Buffer.from('hello'), { contentType: 'text/plain' });
+  if (error) console.error('Error:', error);
+  else console.log('Success:', data);
+}
+run();
diff --git a/test_upload2.js b/test_upload2.js
new file mode 100644
index 0000000..ed9819b
--- /dev/null
+++ b/test_upload2.js
@@ -0,0 +1,10 @@
+require('dotenv').config();
+const { createClient } = require('@supabase/supabase-js');
+const supabase = createClient(process.env.SUPABASE_URL, process.env.SUPABASE_SERVICE_ROLE_KEY);
+
+async function run() {
+  const { data, error } = await supabase.storage.from('case-documents').upload('templates/test_user_id/şablon dosyası.udf', Buffer.from('hello'), { contentType: 'application/octet-stream' });
+  if (error) console.error('Error:', error);
+  else console.log('Success:', data);
+}
+run();