diff --git a/.zshrc b/.zshrc
index 756d603..ba2ca72 100644
--- a/.zshrc
+++ b/.zshrc
@@ -43,11 +43,14 @@ fi
 export BLOCKSIZE="k"
 export EDITOR="vim"
 export GIT_PAGER="less"
+export HISTSIZE=2000
 export LESS="-EfmrSwX"
 export LSCOLORS="gxfxcxdxbxegedabagacad"
 export PATH="$HOME/bin:$HOME/node_modules/.bin:/usr/local/sbin:/usr/sbin:/sbin:$PATH"
 export PERL_CPANM_OPT="--mirror http://cpan.nctu.edu.tw/ --mirror http://cpan.cpantesters.org/"
+export SAVEHIST=2000
 #
+setopt hist_ignore_all_dups
 setopt prompt_subst
 #
 if [[ -z "$WINDOW" ]]; then