diff --git a/.emacs.d/config/c.el b/.emacs.d/config/c.el
index f013035..1373b7b 100644
--- a/.emacs.d/config/c.el
+++ b/.emacs.d/config/c.el
@@ -1,3 +1,8 @@
 ;; set c style to linux and indention to 2
 (setq c-default-style "linux"
       c-basic-offset 2)
+
+(use-package lsp-mode
+  :ensure t
+  :hook
+  (c-mode . lsp-deferred))
diff --git a/.emacs.d/config/dev.el b/.emacs.d/config/dev.el
index 15f4b1f..d6808c7 100644
--- a/.emacs.d/config/dev.el
+++ b/.emacs.d/config/dev.el
@@ -40,7 +40,9 @@
 (add-hook 'prog-mode-hook #'flyspell-prog-mode)
 
 (use-package lsp-mode
-  :ensure t)
+  :ensure t
+  :config
+  (setq lsp-completion-default-behaviour ':insert))
 
 (use-package lsp-ui
   :ensure t
@@ -48,7 +50,8 @@
   ("C-c i" . lsp-ui-doc-show)
   :config
   (setq lsp-ui-doc-position 'at-point)
-  (setq lsp-ui-doc-show-with-mouse nil))
+  (setq lsp-ui-doc-show-with-mouse nil)
+  (setq lsp-ui-sideline-show-diagnostics nil))
 
 (use-package yasnippet
   :ensure t)