diff --git a/backend/internal/api/handlers.go b/backend/internal/api/handlers.go
index db1adcb..d654c94 100644
--- a/backend/internal/api/handlers.go
+++ b/backend/internal/api/handlers.go
@@ -52,6 +52,11 @@ func (h *Handlers) ListFiles(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Ensure we always encode an array, never null
+	if files == nil {
+		files = []*storage.File{}
+	}
+
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(files)
 }
diff --git a/backend/internal/storage/storage.go b/backend/internal/storage/storage.go
index 30032ad..d657ed2 100644
--- a/backend/internal/storage/storage.go
+++ b/backend/internal/storage/storage.go
@@ -44,23 +44,23 @@ func (s *Storage) List() ([]*File, error) {
 		return nil, fmt.Errorf("failed to read directory: %w", err)
 	}
 
-	var files []*File
+	files := make([]*File, 0)
 	for _, entry := range entries {
 		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".md") {
 			continue
 		}
-		
+
 		info, err := entry.Info()
 		if err != nil {
 			continue
 		}
-		
+
 		files = append(files, &File{
 			Name:     entry.Name(),
 			Modified: info.ModTime().Unix(),
 		})
 	}
-	
+
 	logging.Logger.WithField("count", len(files)).Info("Listed files")
 	return files, nil
 }
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index ab09ef2..7f2b85c 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -20,7 +20,7 @@ function App() {
     try {
       setError(null);
       const fetchedFiles = await api.list();
-      setFiles(fetchedFiles);
+      setFiles(fetchedFiles ?? []);
     } catch (err) {
       setError(err instanceof Error ? err.message : 'Failed to load files');
     } finally {
@@ -56,7 +56,7 @@ function App() {
     try {
       setError(null);
       const file = await api.create(name, '# ' + name.replace('.md', '') + '\n\nStart writing here...');
-      setFiles([...files, file]);
+      setFiles([...(files ?? []), file]);
       setSelectedFile(file);
     } catch (err) {
       setError(err instanceof Error ? err.message : 'Failed to create file');
@@ -72,7 +72,7 @@ function App() {
       const updated = await api.update(selectedFile.name, content);
       setSelectedFile(updated);
       setOriginalContent(content);
-      setFiles(files.map((f) => (f.name === updated.name ? updated : f)));
+      setFiles((files ?? []).map((f) => (f.name === updated.name ? updated : f)));
     } catch (err) {
       setError(err instanceof Error ? err.message : 'Failed to save file');
     } finally {
@@ -86,7 +86,7 @@ function App() {
     try {
       setError(null);
       await api.delete(name);
-      setFiles(files.filter((f) => f.name !== name));
+      setFiles((files ?? []).filter((f) => f.name !== name));
       if (selectedFile?.name === name) {
         setSelectedFile(null);
       }
@@ -125,7 +125,7 @@ function App() {
           <div className="grid grid-cols-1 lg:grid-cols-4 gap-4">
             <div className="lg:col-span-1">
               <FileList
-                files={files}
+                files={files ?? []}
                 selectedFile={selectedFile?.name || null}
                 onSelectFile={handleSelectFile}
                 onDeleteFile={handleDeleteFile}
@@ -163,7 +163,7 @@ function App() {
         isOpen={showNewDialog}
         onClose={() => setShowNewDialog(false)}
         onCreate={handleCreateFile}
-        existingNames={files.map((f) => f.name)}
+        existingNames={files?.map((f) => f.name) ?? []}
       />
 
       {hasUnsavedChanges && (