diff --git a/plugins/_whatsapp_integration/helpers/handler.py b/plugins/_whatsapp_integration/helpers/handler.py
index 7b109ba0b..b7a9e49cf 100644
--- a/plugins/_whatsapp_integration/helpers/handler.py
+++ b/plugins/_whatsapp_integration/helpers/handler.py
@@ -237,6 +237,13 @@ async def send_wa_reply(
     if not reply_to and context.data.get(CTX_WA_IS_GROUP):
         reply_to = context.data.get(CTX_WA_LAST_MSG_ID, "")
 
+    # Prefix response in self-chat mode so user can distinguish agent messages
+    mode = config.get("mode", "dedicated")
+    if mode == "self-chat":
+        response_text = context.agent0.read_prompt(
+            "fw.wa.self_chat_prefix.md", response_text=response_text,
+        )
+
     # Send text
     try:
         result = await wa_client.send_message(base_url, chat_id, response_text, reply_to=reply_to)
diff --git a/plugins/_whatsapp_integration/prompts/fw.wa.self_chat_prefix.md b/plugins/_whatsapp_integration/prompts/fw.wa.self_chat_prefix.md
new file mode 100644
index 000000000..7a0cb9806
--- /dev/null
+++ b/plugins/_whatsapp_integration/prompts/fw.wa.self_chat_prefix.md
@@ -0,0 +1,2 @@
+[🤖 Agent Zero]
+{{response_text}}
\ No newline at end of file