diff --git a/hlna-git/postinstall.sh b/hlna-git/postinstall.sh
index 3cc8d30..2957f66 100755
--- a/hlna-git/postinstall.sh
+++ b/hlna-git/postinstall.sh
@@ -1,14 +1,14 @@
 #!/usr/bin/env bash
-if test -e ~/.zshrc; then
-sed -i -e '$aalias hlna="hlna.py"' ~/.zshrc | zsh
-sed -i -e '$aalias hlna-bot="hlna-bot.py"' ~/.zshrc | zshz
+if test -f ~/.zshrc; then
+sed -i -f '$aalias hlna="hlna.py"' ~/.zshrc
+sed -i -f '$aalias hlna-bot="hlna-bot.py"' ~/.zshrc
 source ~/.zshrc
-elif test -e ~/.config/fish/config.fish; then
-sed -i -e '$alias hlna="hlna.py"' ~/.config/fish/config.fish
-sed -i -e '$alias hlna-bot="hlna-bot.py"' ~/.config/fish/config.fish
+elif test -f ~/.config/fish/config.fish; then
+sed -i -f '$alias hlna="hlna.py"' ~/.config/fish/config.fish
+sed -i -f '$alias hlna-bot="hlna-bot.py"' ~/.config/fish/config.fish
 source ~/.config/fish/config.fish
 else
-sed -i -e '$aalias hlna="hlna.py"' ~/.bashrc
-sed -i -e '$aalias hlna-bot="hlna-bot.py"' ~/.bashrc
+sed -i -f '$aalias hlna="hlna.py"' ~/.bashrc
+sed -i -f '$aalias hlna-bot="hlna-bot.py"' ~/.bashrc
 source ~/.bashrc
 fi