diff --git a/application/src/main/java/run/halo/app/content/comment/AbstractCommentService.java b/application/src/main/java/run/halo/app/content/comment/AbstractCommentService.java
index 66f6ee89c..34a50514a 100644
--- a/application/src/main/java/run/halo/app/content/comment/AbstractCommentService.java
+++ b/application/src/main/java/run/halo/app/content/comment/AbstractCommentService.java
@@ -24,7 +24,11 @@ public abstract class AbstractCommentService {
     protected final ReactiveExtensionClient client;
     protected final UserService userService;
     protected final CounterService counterService;
-    private final Safelist safelist = Safelist.relaxed();
+    private final Safelist safelist = Safelist.relaxed()
+        // Allow <s> tag, which is used for strikethrough
+        .addTags("s")
+        // Allow <code> tag's class attribute, for syntax highlighting
+        .addAttributes("code", "class");
 
     protected Mono<User> fetchCurrentUser() {
         return ReactiveSecurityContextHolder.getContext()