diff --git a/lib/src/models/rules/insert.dart b/lib/src/models/rules/insert.dart
index 5a53fbdf..b97058bc 100644
--- a/lib/src/models/rules/insert.dart
+++ b/lib/src/models/rules/insert.dart
@@ -565,8 +565,8 @@ class PreserveInlineStylesRule extends InsertRule {
 
     if ((prev.data as String).endsWith('\n')) {
       if (prev.attributes != null) {
-        for (final value in prev.attributes!.values) {
-          if (!(value as Attribute).isInline) {
+        for (final key in prev.attributes!.keys) {
+          if (!Attribute.inlineKeys.contains(key)) {
             return null;
           }
         }