diff --git a/lib/src/widgets/kanji_card.dart b/lib/src/widgets/kanji_card.dart
index f9095c5..008b272 100644
--- a/lib/src/widgets/kanji_card.dart
+++ b/lib/src/widgets/kanji_card.dart
@@ -44,7 +44,7 @@ class KanjiCard extends StatelessWidget {
               Text(
                 subtitle,
                 style: theme.textTheme.bodyMedium?.copyWith(
-                  color: fgColor.withOpacity(0.7),
+                  color: fgColor.withValues(alpha: 0.7),
                 ),
                 textAlign: TextAlign.center,
               ),