diff --git a/src/main/kotlin/com/android/trisolarisserver/controller/Guests.kt b/src/main/kotlin/com/android/trisolarisserver/controller/Guests.kt
index d5872f8..8c89778 100644
--- a/src/main/kotlin/com/android/trisolarisserver/controller/Guests.kt
+++ b/src/main/kotlin/com/android/trisolarisserver/controller/Guests.kt
@@ -174,7 +174,7 @@ class Guests(
             throw ResponseStatusException(HttpStatus.BAD_REQUEST, "File is empty")
         }
         val contentType = file.contentType ?: ""
-        if (!contentType.equals("image/svg+xml", ignoreCase = true)) {
+        if (!contentType.lowercase().startsWith("image/svg+xml")) {
             throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Only SVG allowed")
         }