diff --git a/README.md b/README.md
index 746666d..1e0fbd0 100644
--- a/README.md
+++ b/README.md
@@ -146,7 +146,7 @@ require("harpoon").setup({
         save_on_toggle = false,
         save_on_change = true,
         enter_on_sendcmd = false,
-        excluded_filetypes = {"harpoon"}
+        excluded_filetypes = { "harpoon" }
     },
     ... your other configs ...
 })
diff --git a/lua/harpoon/init.lua b/lua/harpoon/init.lua
index 85609a2..86300b2 100644
--- a/lua/harpoon/init.lua
+++ b/lua/harpoon/init.lua
@@ -157,7 +157,7 @@ M.setup = function(config)
             ["save_on_toggle"] = false,
             ["save_on_change"] = true,
             ["enter_on_sendcmd"] = false,
-            ["excluded_filetypes"] = {"harpoon"}
+            ["excluded_filetypes"] = { "harpoon" },
         },
     }, expand_dir(
         c_config
diff --git a/lua/harpoon/mark.lua b/lua/harpoon/mark.lua
index 53f4346..14817fe 100644
--- a/lua/harpoon/mark.lua
+++ b/lua/harpoon/mark.lua
@@ -118,10 +118,21 @@ end
 local function filter_filetype()
     local current_filetype = vim.bo.filetype
     local excluded_filetypes = harpoon.get_global_settings().excluded_filetypes
+
+    if current_filetype == "harpoon" then
+        log.error("filter_filetype(): You can't add harpoon to the harpoon")
+        error("You can't add harpoon to the harpoon")
+        return
+    end
+
     for filetype = 1, #excluded_filetypes do
-        if(current_filetype == excluded_filetypes[filetype] or current_filetype == "harpoon") then
-            log.error('filter_filetype(): This filetype cannot be added or is included in the "excluded_filetypes" option')
-            error('This filetype cannot be added or is included in the "excluded_filetypes" option')
+        if current_filetype == excluded_filetypes[filetype] then
+            log.error(
+                'filter_filetype(): This filetype cannot be added or is included in the "excluded_filetypes" option'
+            )
+            error(
+                'This filetype cannot be added or is included in the "excluded_filetypes" option'
+            )
             return
         end
     end
@@ -192,7 +203,7 @@ M.valid_index = function(idx)
 end
 
 M.add_file = function(file_name_or_buf_id)
-    filter_filetype();
+    filter_filetype()
     local buf_name = get_buf_name(file_name_or_buf_id)
     log.trace("add_file():", buf_name)
 
@@ -309,7 +320,6 @@ M.set_current_at = function(idx)
     local config = harpoon.get_mark_config()
     local current_idx = M.get_index_of(buf_name)
 
-
     -- Remove it if it already exists
     if M.valid_index(current_idx) then
         config.marks[current_idx] = create_mark("")