diff --git a/backend/uploads.go b/backend/uploads.go
index 20d88f7..5d9ddc5 100644
--- a/backend/uploads.go
+++ b/backend/uploads.go
@@ -28,7 +28,7 @@ func sanitizeDescriptor(s string) string {
 	var b []rune
 	lastUnderscore := false
 	for _, r := range s {
-		ok := (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') || (r >= '0' && r <= '9') || r == '_' || r == '-'
+		ok := strings.ContainsRune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-", r)
 		if !ok {
 			r = '_'
 		}