diff --git a/storage/filesystem.go b/storage/filesystem.go
index d958331..72b8188 100644
--- a/storage/filesystem.go
+++ b/storage/filesystem.go
@@ -135,7 +135,7 @@ func createDefaultAddressBook(path string) error {
 		Name:                 "My contacts",
 		Description:          "Default address book",
 		MaxResourceSize:      1024,
-		SupportedAddressData: []carddav.AddressDataType{},
+		SupportedAddressData: nil,
 	}
 	blob, err := json.MarshalIndent(defaultAB, "", "  ")
 	if err != nil {
@@ -211,7 +211,7 @@ func (b *filesystemBackend) GetAddressObject(ctx context.Context, path string, r
 }
 
 func (b *filesystemBackend) loadAll(ctx context.Context, propFilter []string) ([]carddav.AddressObject, error) {
-	result := []carddav.AddressObject{}
+	var result []carddav.AddressObject
 
 	path, err := b.pathForContext(ctx)
 	if err != nil {