diff --git a/crates/buzz-sdk/src/builders.rs b/crates/buzz-sdk/src/builders.rs
index c3b4432101..948fa775f5 100644
--- a/crates/buzz-sdk/src/builders.rs
+++ b/crates/buzz-sdk/src/builders.rs
@@ -239,7 +239,9 @@ pub fn build_message(
         tags.push(tag(&["broadcast", "1"])?);
     }
     imeta_tags(media_tags, &mut tags)?;
-    Ok(EventBuilder::new(Kind::Custom(9), content).tags(tags))
+    Ok(EventBuilder::new(Kind::Custom(9), content)
+        .tags(tags)
+        .allow_self_tagging())
 }
 
 /// Build an encrypted agent observer frame (kind 24200).
@@ -290,7 +292,9 @@ pub fn build_forum_post(
     let mut tags = vec![tag(&["h", &channel_id.to_string()])?];
     mention_tags(mentions, &mut tags)?;
     imeta_tags(media_tags, &mut tags)?;
-    Ok(EventBuilder::new(Kind::Custom(45001), content).tags(tags))
+    Ok(EventBuilder::new(Kind::Custom(45001), content)
+        .tags(tags)
+        .allow_self_tagging())
 }
 
 /// Build a forum comment reply (kind 45003).
@@ -306,7 +310,9 @@ pub fn build_forum_comment(
     thread_tags(thread_ref, &mut tags)?;
     mention_tags(mentions, &mut tags)?;
     imeta_tags(media_tags, &mut tags)?;
-    Ok(EventBuilder::new(Kind::Custom(45003), content).tags(tags))
+    Ok(EventBuilder::new(Kind::Custom(45003), content)
+        .tags(tags)
+        .allow_self_tagging())
 }
 
 /// Build a diff/patch message (kind 40008).
@@ -2253,6 +2259,53 @@ mod tests {
         assert!(has_tag(&ev, "h", &cid.to_string()));
     }
 
+    #[test]
+    fn message_preserves_self_mention_p_tag() {
+        // nostr 0.44 strips p tags matching the signer by default.
+        // build_message must opt in via allow_self_tagging() so that
+        // explicit self-mentions survive signing. See #4906.
+        let cid = uuid();
+        let sender = keys();
+        let self_pk = sender.public_key().to_hex();
+        let builder = build_message(cid, "self-canary", None, &[&self_pk], false, &[]).unwrap();
+        let ev = builder.sign_with_keys(&sender).expect("sign");
+        assert!(
+            has_tag(&ev, "p", &self_pk),
+            "self-mention p tag must survive signing"
+        );
+    }
+
+    #[test]
+    fn forum_post_preserves_self_mention_p_tag() {
+        let cid = uuid();
+        let sender = keys();
+        let self_pk = sender.public_key().to_hex();
+        let builder = build_forum_post(cid, "self-canary", &[&self_pk], &[]).unwrap();
+        let ev = builder.sign_with_keys(&sender).expect("sign");
+        assert!(
+            has_tag(&ev, "p", &self_pk),
+            "self-mention p tag must survive signing"
+        );
+    }
+
+    #[test]
+    fn forum_comment_preserves_self_mention_p_tag() {
+        let cid = uuid();
+        let sender = keys();
+        let self_pk = sender.public_key().to_hex();
+        let root = event_id();
+        let tr = ThreadRef {
+            root_event_id: root,
+            parent_event_id: root,
+        };
+        let builder = build_forum_comment(cid, "self-canary", &tr, &[&self_pk], &[]).unwrap();
+        let ev = builder.sign_with_keys(&sender).expect("sign");
+        assert!(
+            has_tag(&ev, "p", &self_pk),
+            "self-mention p tag must survive signing"
+        );
+    }
+
     #[test]
     fn agent_observer_frame_happy_path() {
         let sender = keys();