diff --git a/lua/CopilotChat/copilot.lua b/lua/CopilotChat/copilot.lua
index fdceaa3e..a8074525 100644
--- a/lua/CopilotChat/copilot.lua
+++ b/lua/CopilotChat/copilot.lua
@@ -9,6 +9,8 @@
 ---@field embeddings table<CopilotChat.copilot.embed>?
 ---@field filename string?
 ---@field filetype string?
+---@field start_row number?
+---@field end_row number?
 ---@field system_prompt string?
 ---@field model string?
 ---@field temperature number?
@@ -91,12 +93,24 @@ local function get_cached_token()
   return userdata['github.com'].oauth_token
 end
 
-local function generate_selection_message(filename, filetype, selection)
+local function generate_selection_message(filename, filetype, start_row, end_row, selection)
   if not selection or selection == '' then
     return ''
   end
 
-  return string.format('Active selection: `%s`\n```%s\n%s\n```', filename, filetype, selection)
+  local content = selection
+  if start_row > 0 then
+    local lines = vim.split(selection, '\n')
+    local total_lines = #lines
+    local max_length = #tostring(total_lines)
+    for i, line in ipairs(lines) do
+      local formatted_line_number = string.format('%' .. max_length .. 'd', i - 1 + start_row)
+      lines[i] = formatted_line_number .. ': ' .. line
+    end
+    content = table.concat(lines, '\n')
+  end
+
+  return string.format('Active selection: `%s`\n```%s\n%s\n```', filename, filetype, content)
 end
 
 local function generate_embeddings_message(embeddings)
@@ -156,7 +170,6 @@ local function generate_ask_request(
   end
 
   if embeddings and #embeddings.files > 0 then
-    -- FIXME: Is this really supposed to be sent like this? Maybe just send it with query, not sure
     table.insert(messages, {
       content = embeddings.header .. table.concat(embeddings.files, ''),
       role = 'system',
@@ -300,6 +313,8 @@ function Copilot:ask(prompt, opts)
   local filename = opts.filename or ''
   local filetype = opts.filetype or ''
   local selection = opts.selection or ''
+  local start_row = opts.start_row or 0
+  local end_row = opts.end_row or 0
   local system_prompt = opts.system_prompt or prompts.COPILOT_INSTRUCTIONS
   local model = opts.model or 'gpt-4'
   local temperature = opts.temperature or 0.1
@@ -325,7 +340,8 @@ function Copilot:ask(prompt, opts)
     self:stop()
   end
 
-  local selection_message = generate_selection_message(filename, filetype, selection)
+  local selection_message =
+    generate_selection_message(filename, filetype, start_row, end_row, selection)
   local embeddings_message = generate_embeddings_message(embeddings)
 
   -- Count tokens
diff --git a/lua/CopilotChat/init.lua b/lua/CopilotChat/init.lua
index 88f6c0b4..d7c18edf 100644
--- a/lua/CopilotChat/init.lua
+++ b/lua/CopilotChat/init.lua
@@ -397,6 +397,8 @@ function M.ask(prompt, config, source)
         embeddings = embeddings,
         filename = filename,
         filetype = filetype,
+        start_row = selection.start_row,
+        end_row = selection.end_row,
         system_prompt = system_prompt,
         model = config.model,
         temperature = config.temperature,
diff --git a/lua/CopilotChat/prompts.lua b/lua/CopilotChat/prompts.lua
index bc2737a3..2cd385c9 100644
--- a/lua/CopilotChat/prompts.lua
+++ b/lua/CopilotChat/prompts.lua
@@ -23,7 +23,7 @@ Copilot MUST decline to respond if the question is against Microsoft content pol
 Copilot MUST decline to answer if the question is not related to a developer.
 If the question is related to a developer, Copilot MUST respond with content related to a developer.
 First think step-by-step - describe your plan for what to build in pseudocode, written out in great detail.
-Then output the code in a single code block.
+Then output the code in a single code block. This code block should not contain line numbers (line numbers are not necessary for the code to be understood, they are in format number: at beginning of lines).
 Minimize any other prose.
 Keep your answers short and impersonal.
 Use Markdown formatting in your answers.