diff --git a/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/composer/NewMessageTaggerKeyParseTest.kt b/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/composer/NewMessageTaggerKeyParseTest.kt
index 582c55e918..d5c6bea949 100644
--- a/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/composer/NewMessageTaggerKeyParseTest.kt
+++ b/commons/src/jvmTest/kotlin/com/vitorpamplona/amethyst/commons/model/composer/NewMessageTaggerKeyParseTest.kt
@@ -209,4 +209,15 @@ class NewMessageTaggerKeyParseTest {
 
             assertTrue(tagger.message.startsWith("hi nostr:nprofile1"))
         }
+
+    @Test
+    fun possessiveAtMentionBecomesNostrUri() =
+        runBlocking {
+            val npub = "npub19ma2w9dmk3kat0nt0k5dwuqzvmg3va9ezwup0zkakhpwv0vcwvcsg8axkl"
+            val tagger = NewMessageTagger(message = "@$npub's ERP screens look good", dao = dao)
+            tagger.run()
+
+            val nprofile = tagger.pTags!!.single().toNProfile()
+            assertEquals("nostr:$nprofile's ERP screens look good", tagger.message)
+        }
 }
diff --git a/commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/screen/loggedIn/chats/privateDM/send/ChatNewMessageViewModel.kt b/commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/screen/loggedIn/chats/privateDM/send/ChatNewMessageViewModel.kt
index b99fa90af4..aad92f05f9 100644
--- a/commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/screen/loggedIn/chats/privateDM/send/ChatNewMessageViewModel.kt
+++ b/commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/screen/loggedIn/chats/privateDM/send/ChatNewMessageViewModel.kt
@@ -603,7 +603,13 @@ class ChatNewMessageViewModel :
     ) {
         val room = room.value ?: return
 
-        val messageText = message.text.toString()
+        // Rewrites typed `@npub…`/`note1…` references into `nostr:` URIs. Only the rewritten text is
+        // used: the tagger's pTags must NOT reach the event, since a NIP-17 room is defined by its
+        // p-tags — adding a mentioned user would send the message to a different conversation.
+        val tagger = NewMessageTagger(message.text.toString(), null, null, accountViewModel)
+        tagger.run()
+
+        val messageText = tagger.message
         val urls = findURLs(messageText)
         val usedAttachments = iMetaAttachments.filterIsIn(urls.toSet())
         val emojis = accountViewModel.account.emoji.findEmojiTags(messageText)