diff --git a/add-submodules.sh b/add-submodules.sh
index c395c1e..96e7f25 100755
--- a/add-submodules.sh
+++ b/add-submodules.sh
@@ -54,7 +54,7 @@ remove_old_submodule() {
   local name="$1" path="$2"
 
   # Remove working tree
-  if [ -d "$path" ]; then
+  if [[ -d "$path" ]]; then
     rm -rf "$path"
     _log "Removed $path"
   fi
@@ -66,13 +66,13 @@ remove_old_submodule() {
   git config --remove-section "submodule.$path" 2> /dev/null || true
 
   # Skip name-based cleanup if no submodule name provided
-  [ -z "$name" ] && return 0
+  [[ -z "$name" ]] && return 0
 
   # Remove .git/config section keyed by name
   git config --remove-section "submodule.$name" 2> /dev/null || true
 
   # Remove .git/modules/<name>/ cached repository
-  if [ -d ".git/modules/$name" ]; then
+  if [[ -d ".git/modules/$name" ]]; then
     rm -rf ".git/modules/$name"
     _log "Removed .git/modules/$name"
   fi
diff --git a/config/husky/init.sh b/config/husky/init.sh
index fbb782e..b7e59c2 100755
--- a/config/husky/init.sh
+++ b/config/husky/init.sh
@@ -1,4 +1,4 @@
 #!/bin/env bash
 
-[ -z "$NVM_DIR" ] && export NVM_DIR="$HOME/.config/nvm"
-[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm
+[[ -z "$NVM_DIR" ]] && export NVM_DIR="$HOME/.config/nvm"
+[[ -s "$NVM_DIR/nvm.sh" ]] && \. "$NVM_DIR/nvm.sh" # This loads nvm
diff --git a/config/shared.sh b/config/shared.sh
index ecffc60..309444e 100755
--- a/config/shared.sh
+++ b/config/shared.sh
@@ -5,7 +5,7 @@
 # shellcheck shell=bash
 
 # Defaults
-[ -z "$DOTFILES" ] && export DOTFILES="$HOME/.dotfiles"
+[[ -z "$DOTFILES" ]] && export DOTFILES="$HOME/.dotfiles"
 DOTFILES_CURRENT_SHELL=$(basename "$SHELL")
 export DOTFILES_CURRENT_SHELL
 
@@ -15,7 +15,7 @@ VERBOSE="${VERBOSE:-0}"
 DEBUG="${DEBUG:-0}"
 
 # Enable debugging with DEBUG=1
-[ "${DEBUG:-0}" -eq 1 ] && set -x
+[[ "${DEBUG:-0}" -eq 1 ]] && set -x
 
 # Detect the current shell
 CURRENT_SHELL=$(ps -p $$ -ocomm= | awk -F/ '{print $NF}')
@@ -74,7 +74,7 @@ x-path-prepend "$DOTFILES/local/bin"
 x-path-prepend "$XDG_BIN_HOME"
 
 # Custom completion paths
-[ -z "$ZSH_CUSTOM_COMPLETION_PATH" ] && export ZSH_CUSTOM_COMPLETION_PATH="$XDG_CONFIG_HOME/zsh/completion"
+[[ -z "$ZSH_CUSTOM_COMPLETION_PATH" ]] && export ZSH_CUSTOM_COMPLETION_PATH="$XDG_CONFIG_HOME/zsh/completion"
 x-dc "$ZSH_CUSTOM_COMPLETION_PATH"
 export FPATH="$ZSH_CUSTOM_COMPLETION_PATH:$FPATH"
 
@@ -83,7 +83,7 @@ if ! declare -f msg > /dev/null; then
   # $1 - message (string)
   msg()
   {
-    [ "$VERBOSE" -eq 1 ] && msgr msg "$1"
+    [[ "$VERBOSE" -eq 1 ]] && msgr msg "$1"
     return 0
   }
   msg "msg was not defined, defined it now"
diff --git a/config/tmux/rename-session.sh b/config/tmux/rename-session.sh
index 84aaf7e..7696107 100755
--- a/config/tmux/rename-session.sh
+++ b/config/tmux/rename-session.sh
@@ -7,13 +7,13 @@ DEFAULT_NAME="main"
 CURRENT_SESSION=$(tmux display-message -p "#{session_name}")
 
 # Check that the session has a name
-if [ "$CURRENT_SESSION" = "#{session_name}" ] || [ "$CURRENT_SESSION" = "0" ]; then
+if [[ "$CURRENT_SESSION" = "#{session_name}" ]] || [[ "$CURRENT_SESSION" = "0" ]]; then
   # Check if the default name is already in use
   if tmux has-session -t "$DEFAULT_NAME" 2> /dev/null; then
     # Query the user for a new name
     echo "Session name '$DEFAULT_NAME' is already in use. Enter a new name:"
     read -r NEW_NAME
-    while tmux has-session -t "$NEW_NAME" 2> /dev/null || [ -z "$NEW_NAME" ]; do
+    while tmux has-session -t "$NEW_NAME" 2> /dev/null || [[ -z "$NEW_NAME" ]]; do
       echo "Name '$NEW_NAME' is invalid or already in use. Enter a new name:"
       read -r NEW_NAME
     done
diff --git a/scripts/install-cheat-purebashbible.sh b/scripts/install-cheat-purebashbible.sh
index fc6606a..5759be1 100755
--- a/scripts/install-cheat-purebashbible.sh
+++ b/scripts/install-cheat-purebashbible.sh
@@ -24,7 +24,7 @@ check_required_tools()
 
 clone_or_update_repo()
 {
-  if [ ! -d "$PBB_TEMP_DIR/.git" ]; then
+  if [[ ! -d "$PBB_TEMP_DIR/.git" ]]; then
     msg_run "Starting to clone $PBB_GIT"
     git clone --depth 1 --single-branch -q "$PBB_GIT" "$PBB_TEMP_DIR" \
       && msg_yay "Cloned $PBB_GIT"
@@ -41,7 +41,7 @@ prepare_cheat_dest()
   local cheat_dest
   cheat_dest="$(cheat -d | grep pure-bash-bible | head -1 | awk '{print $2}')"
 
-  if [ ! -d "$cheat_dest" ]; then
+  if [[ ! -d "$cheat_dest" ]]; then
     mkdir -p "$cheat_dest"
   fi
 
@@ -83,7 +83,7 @@ process_chapters()
     LC_ALL=C perl -pi.bak -e 's/\<\!-- CHAPTER END --\>//' "$cheat_file"
     rm "$cheat_file.bak"
 
-    if [ '---' != "$(head -1 < "$cheat_file")" ]; then
+    if [[ '---' != "$(head -1 < "$cheat_file")" ]]; then
       local metadata
       metadata="$PBB_SYNTAX\n$PBB_TAGS\n$PBB_SOURCE\n"
       printf '%s\n%b%s\n%s' "---" "$metadata" "---" "$(cat "$cheat_file")" > "$cheat_file"
diff --git a/scripts/install-composer.sh b/scripts/install-composer.sh
index b708b00..d23c094 100755
--- a/scripts/install-composer.sh
+++ b/scripts/install-composer.sh
@@ -14,7 +14,7 @@ EXPECTED_CHECKSUM="$(php -r 'copy("https://composer.github.io/installer.sig", "p
 php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
 ACTUAL_CHECKSUM="$(php -r "echo hash_file('sha384', 'composer-setup.php');")"
 
-if [ "$EXPECTED_CHECKSUM" != "$ACTUAL_CHECKSUM" ]; then
+if [[ "$EXPECTED_CHECKSUM" != "$ACTUAL_CHECKSUM" ]]; then
   echo >&2 'ERROR: Invalid installer checksum'
   rm composer-setup.php
   exit 1
@@ -23,7 +23,7 @@ fi
 php composer-setup.php --quiet
 RESULT=$?
 rm composer-setup.php
-if [ $RESULT -eq 0 ]; then
+if [[ $RESULT -eq 0 ]]; then
   mv composer.phar ~/.local/bin/composer
 fi
 exit $RESULT
diff --git a/scripts/install-fonts.sh b/scripts/install-fonts.sh
index 910a474..aa6eff8 100755
--- a/scripts/install-fonts.sh
+++ b/scripts/install-fonts.sh
@@ -18,7 +18,7 @@ fonts=(
 # Function to clone or update the NerdFonts repository
 clone_or_update_repo()
 {
-  if [ ! -d "$TMP_PATH" ]; then
+  if [[ ! -d "$TMP_PATH" ]]; then
     git clone --quiet --filter=blob:none --sparse --depth=1 "$GIT_REPO" "$TMP_PATH"
   fi
 
diff --git a/scripts/install-git-crypt.sh b/scripts/install-git-crypt.sh
index 575146c..86ad529 100755
--- a/scripts/install-git-crypt.sh
+++ b/scripts/install-git-crypt.sh
@@ -15,7 +15,7 @@ if ! command -v git-crypt &> /dev/null; then
   BUILD_PATH="$(mktemp -d)"
   trap 'rm -rf "$BUILD_PATH"' EXIT
 
-  if [ ! -f "$CHECK_PATH" ]; then
+  if [[ ! -f "$CHECK_PATH" ]]; then
     git clone --depth 1 "$REPO_URL" "$BUILD_PATH" || { msgr err "Failed to clone $REPO_URL"; exit 1; }
     cd "$BUILD_PATH" || { msgr err "$BUILD_PATH not found"; exit 1; }
     make && make install PREFIX="$HOME/.local"
diff --git a/scripts/install-macos-defaults.sh b/scripts/install-macos-defaults.sh
index 6e7fef2..9b049d1 100755
--- a/scripts/install-macos-defaults.sh
+++ b/scripts/install-macos-defaults.sh
@@ -5,7 +5,7 @@ set -uo pipefail
 # This script contains large portions from following scripts:
 # - https://github.com/freekmurze/dotfiles/blob/main/macos/set-defaults.sh
 
-[ "$(uname)" != "Darwin" ] && echo "Not a macOS system" && exit 0
+[[ "$(uname)" != "Darwin" ]] && echo "Not a macOS system" && exit 0
 
 # shellcheck source=shared.sh
 source "$DOTFILES/config/shared.sh"
diff --git a/scripts/install-ntfy.sh b/scripts/install-ntfy.sh
index 0dfeb7e..1dcadd2 100755
--- a/scripts/install-ntfy.sh
+++ b/scripts/install-ntfy.sh
@@ -43,7 +43,7 @@ install_ntfy()
   mkdir -p ~/.config/ntfy
 
   # Copy config only if it does not exist
-  if [ ! -f "$HOME/.config/ntfy/client.yml" ]; then
+  if [[ ! -f "$HOME/.config/ntfy/client.yml" ]]; then
     cp "$tmpdir/${NTFY_DIR}/client/client.yml" ~/.config/ntfy/client.yml
   fi
 }
diff --git a/scripts/install-xcode-cli-tools.sh b/scripts/install-xcode-cli-tools.sh
index e9172db..55d816d 100755
--- a/scripts/install-xcode-cli-tools.sh
+++ b/scripts/install-xcode-cli-tools.sh
@@ -5,7 +5,7 @@ set -euo pipefail
 #
 
 # Check if the script is running on macOS
-if [ "$(uname)" != "Darwin" ]; then
+if [[ "$(uname)" != "Darwin" ]]; then
   msgr warn "Not a macOS system"
   exit 0
 fi
@@ -40,7 +40,7 @@ prompt_xcode_install()
       'tell app "System Events" to display dialog "Please click install when Command Line Developer Tools appears"'
   )"
 
-  if [ "$XCODE_MESSAGE" = "button returned:OK" ]; then
+  if [[ "$XCODE_MESSAGE" = "button returned:OK" ]]; then
     xcode-select --install
   else
     msgr warn "You have cancelled the installation, please rerun the installer."
@@ -53,13 +53,13 @@ main()
 {
   keep_alive_sudo
 
-  if [ -x "$XCODE_SWIFT_PATH" ]; then
+  if [[ -x "$XCODE_SWIFT_PATH" ]]; then
     msgr run "You have swift from xcode-select. Continuing..."
   else
     prompt_xcode_install
   fi
 
-  until [ -f "$XCODE_SWIFT_PATH" ]; do
+  until [[ -f "$XCODE_SWIFT_PATH" ]]; do
     echo -n "."
     sleep 1
   done
diff --git a/scripts/install-z.sh b/scripts/install-z.sh
index 0d6e192..3e63920 100755
--- a/scripts/install-z.sh
+++ b/scripts/install-z.sh
@@ -14,7 +14,7 @@ clone_z_repo()
   local git_path=$1
   local bin_path=$2
 
-  if [ ! -d "$bin_path" ]; then
+  if [[ ! -d "$bin_path" ]]; then
     git clone "$git_path" "$bin_path"
     msgr run_done "z installed at $bin_path"
   else
diff --git a/scripts/shared.sh b/scripts/shared.sh
index 5baf586..6775c06 100755
--- a/scripts/shared.sh
+++ b/scripts/shared.sh
@@ -5,7 +5,7 @@
 : "${VERBOSE:=0}"
 
 # Source the main shared config if not already loaded
-if [ -z "${SHARED_SCRIPTS_SOURCED:-}" ]; then
+if [[ -z "${SHARED_SCRIPTS_SOURCED:-}" ]]; then
   source "${DOTFILES}/config/shared.sh"
   export SHARED_SCRIPTS_SOURCED=1
 fi
diff --git a/test-all.sh b/test-all.sh
index 3ff0d54..d05b5d3 100755
--- a/test-all.sh
+++ b/test-all.sh
@@ -3,7 +3,7 @@
 
 set -euo pipefail
 
-if [ -x "node_modules/bats/bin/bats" ]; then
+if [[ -x "node_modules/bats/bin/bats" ]]; then
   git ls-files '*.bats' -z | xargs -0 node_modules/bats/bin/bats
 elif command -v npx > /dev/null; then
   git ls-files '*.bats' -z | xargs -0 npx --yes bats