diff --git a/bin/main.dart b/bin/main.dart
index 6c76070..5b0c174 100644
--- a/bin/main.dart
+++ b/bin/main.dart
@@ -42,17 +42,15 @@ void main(List<String> argsRaw) async {
                 );
               }
 
-              final authHeaders = <String, String>{};
-              for (var header in [
-                'authorization',
-                'x-amz-date',
-                'x-amz-content-sha256',
-              ]) {
-                final value = authResponse.headers[header];
-                if (value != null) {
-                  authHeaders[header] = value;
-                }
-              }
+              final authHeaders = {
+                for (final header in [
+                  'authorization',
+                  'x-amz-date',
+                  'x-amz-content-sha256',
+                ])
+                  if (authResponse.headers[header] case final value?)
+                    header: value,
+              };
 
               final minioUrl = settings.minioUri.replace(
                 path: "/lasuite-docs/$path",