diff --git a/mappings.vim b/mappings.vim
index 2c8bf65..a5c200c 100644
--- a/mappings.vim
+++ b/mappings.vim
@@ -110,6 +110,10 @@ inoremap <expr> <esc> ((pumvisible())?("\<C-e>"):("\<esc>"))
 inoremap <expr> <tab> pumvisible() ? "\<c-n>" : "\<tab>"
 inoremap <expr> <s-tab> pumvisible() ? "\<c-p>" : "\<s-tab>"
 
+" Use <c-d> and <c-u> to scroll the completion menu.
+inoremap <expr> <C-d> pumvisible() ? "\<PageDown>" : "\<C-d>"
+inoremap <expr> <C-u> pumvisible() ? "\<PageUp>" : "\<C-u>"
+
 " Edit and reload init.vim quickly
 nnoremap <silent> <leader>ev :tabnew $MYVIMRC <bar> tcd %:h<cr>
 nnoremap <silent> <leader>sv :silent update $MYVIMRC <bar> source $MYVIMRC <bar>