diff --git a/.bash_aliases b/.bash_aliases
old mode 100644
new mode 100755
index 9ab7054..13f325c
--- a/.bash_aliases
+++ b/.bash_aliases
@@ -1,3 +1,5 @@
+#! /usr/bin/bash
+
 alias ll="exa --binary --long"
 alias la="ll --all"
 alias tree="ll --tree"
diff --git a/.bashrc b/.bashrc
old mode 100644
new mode 100755
index 1bf1305..2c1d8a2
--- a/.bashrc
+++ b/.bashrc
@@ -1,3 +1,5 @@
+#! /usr/bin/bash
+
 # ~/.bashrc: executed by bash(1) for non-login shells.
 # see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
 # for examples
@@ -74,7 +76,11 @@ esac
 
 # enable color support of ls and also add handy aliases
 if [ -x /usr/bin/dircolors ]; then
-    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
+    if test -r ~/.dircolors; then
+        eval "$(dircolors -b ~/.dircolors)"
+    else
+        eval "$(dircolors -b)"
+    fi
     alias ls='ls --color=auto'
     #alias dir='dir --color=auto'
     #alias vdir='vdir --color=auto'
@@ -102,6 +108,7 @@ alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo
 # See /usr/share/doc/bash-doc/examples in the bash-doc package.
 
 if [ -f ~/.bash_aliases ]; then
+    # shellcheck source=/dev/null
     . ~/.bash_aliases
 fi
 
@@ -121,4 +128,5 @@ eval "$(direnv hook bash)"
 . "$HOME/.cargo/env"
 
 # Tell GPG in where to open the pinentry dialog
-export GPG_TTY="$(tty)"
+GPG_TTY="$(tty)"
+export GPG_TTY
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index a9baa7a..c7ea0de 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -26,3 +26,4 @@ repos:
   hooks:
   - id: forbid-binary
     exclude: ^\.local/share/jupyter/kernels/python3\.12/logo-
+  - id: shellcheck