diff --git a/lib/services/protocol_blocking_service.dart b/lib/services/protocol_blocking_service.dart
index 55d76c8..9df0efb 100644
--- a/lib/services/protocol_blocking_service.dart
+++ b/lib/services/protocol_blocking_service.dart
@@ -234,7 +234,9 @@ class ProtocolBlockingService {
     final asciiData = _extractAsciiFromHex(hexBytes);
     final hexString = hexBytes.join('').toLowerCase();
     
-    print('🔤 ASCII sample: ${asciiData.replaceAll(RegExp(r'[^\x20-\x7E]'), '.').substring(0, 100)}...');
+    final cleanAscii = asciiData.replaceAll(RegExp(r'[^\x20-\x7E]'), '.');
+    final sampleLength = cleanAscii.length < 100 ? cleanAscii.length : 100;
+    print('🔤 ASCII sample: ${cleanAscii.substring(0, sampleLength)}${cleanAscii.length > 100 ? '...' : ''}');
     
     String? detectedProtocol;