diff --git a/lib/grep.zsh b/lib/grep.zsh
index 93c4270b6..86660cf0d 100644
--- a/lib/grep.zsh
+++ b/lib/grep.zsh
@@ -2,5 +2,5 @@
 # Color grep results
 # Examples: http://rubyurl.com/ZXv
 #
-export GREP_OPTIONS='--color=auto'
-export GREP_COLOR='1;32'
\ No newline at end of file
+GREP_OPTIONS=${GREP_OPTIONS:-'--color=auto'}; export GREP_OPTIONS
+GREP_COLOR=${GREP_COLOR:-'1;32'}; export GREP_COLOR
diff --git a/lib/misc.zsh b/lib/misc.zsh
index 4c1743657..d6bd49ef0 100644
--- a/lib/misc.zsh
+++ b/lib/misc.zsh
@@ -9,5 +9,5 @@ bindkey "^[m" copy-prev-shell-word
 setopt long_list_jobs
 
 ## pager
-export PAGER=less
-export LC_CTYPE=en_US.UTF-8
+PAGER=${PAGER:-less}; export PAGER
+LC_CTYPE=${LC_CTYPE:-en_US.UTF-8}; export LC_CTYPE