diff --git a/lua/gemini/chat.lua b/lua/gemini/chat.lua
index e803871..b13b51f 100644
--- a/lua/gemini/chat.lua
+++ b/lua/gemini/chat.lua
@@ -111,13 +111,16 @@ function M.create_window()
     end
 end
 
-function M.update_content(content, is_new_chat)
+function M.update_content(content, is_new_chat, is_thinking)
     vim.api.nvim_buf_set_option(state.bufnr, 'modifiable', true)
 
     local lines = vim.split(content, "\n")
     
-    if #state.conversation_history > 1 then  -- Check if there's more than one message
-        -- Add separator before new content
+    -- Only add separator if:
+    -- 1. Not the first message
+    -- 2. Not a thinking message
+    -- 3. There's existing content in the buffer
+    if not is_thinking and not is_new_chat and vim.api.nvim_buf_line_count(state.bufnr) > 0 then
         local separator = "━━━━━━━━━━━━━━━━━━━━━━━━━━"
         table.insert(lines, 1, separator)
     end