diff --git a/spacemacs/packages.el b/spacemacs/packages.el
index 484da3d18..21188209a 100644
--- a/spacemacs/packages.el
+++ b/spacemacs/packages.el
@@ -362,8 +362,6 @@ which require an initialization must be listed explicitly in the list."
       (require 'auto-complete-config)
       (ac-config-default)
       (add-to-list 'completion-styles 'initials t)
-      (add-to-list 'ac-sources 'ac-source-semantic)
-      (semantic-mode t)
       ;; customization
       (setq ac-auto-start 2
             ac-delay 0.