diff --git a/developer/bin/develop_brew_cask b/developer/bin/develop_brew_cask
index 17f0943ac5..5d82071eaa 100755
--- a/developer/bin/develop_brew_cask
+++ b/developer/bin/develop_brew_cask
@@ -21,7 +21,7 @@ cd_to_project_root () {
 cd_to_version_dir () {
     local cellar_dir="$1"
     local version_dir="$2"
-    if [ -z "$version_dir" ]; then
+    if [[ -z "$version_dir" ]]; then
         printf "Can't get version dir under $cellar_dir/\n";
         exit 1;
     fi
@@ -31,15 +31,15 @@ cd_to_version_dir () {
 create_dev_links () {
     local git_root="$1"
     local tap_dir="$2"
-    mv rubylib production_rubylib
-    mv Casks   production_Casks
-    ln -s "$git_root/Casks" .
-    ln -s "$git_root/lib"   rubylib
+    /bin/mv rubylib production_rubylib
+    /bin/mv Casks   production_Casks
+    /bin/ln -s "$git_root/Casks" .
+    /bin/ln -s "$git_root/lib"   rubylib
     cd "$tap_dir"
-    mv lib   production_lib
-    mv Casks production_Casks
-    ln -s "$git_root/Casks" .
-    ln -s "$git_root/lib"   .
+    /bin/mv lib   production_lib
+    /bin/mv Casks production_Casks
+    /bin/ln -s "$git_root/Casks" .
+    /bin/ln -s "$git_root/lib"   .
 }
 
 _develop_brew_cask () {
@@ -49,21 +49,21 @@ _develop_brew_cask () {
 
     # initialization
     cd_to_project_root;
-    local git_root=`pwd`
+    local git_root="$(pwd)"
     local brew_prefix="$(brew --prefix)"
     local cellar_dir="$brew_prefix/Cellar/brew-cask"
-    local version_dir=$(/bin/ls "$cellar_dir/" | sort | tail -1)
+    local version_dir="$(/bin/ls "$cellar_dir/" | /usr/bin/sort | /usr/bin/tail -1)"
     local tap_dir="$brew_prefix/$tap_subdir"
 
     # sanity check
-    if [[ $(/usr/bin/stat -L -f '%i' "$tap_dir") -eq $(/usr/bin/stat -L -f '%i' "$git_root") ]]; then
+    if [[ "$(/usr/bin/stat -L -f '%i' "$tap_dir")" -eq "$(/usr/bin/stat -L -f '%i' "$git_root")" ]]; then
         printf "\nERROR: run this script in your private repo, not inside Homebrew.\n";
         exit 1;
     fi
 
     # action
     cd_to_version_dir "$cellar_dir" "$version_dir";
-    if [ -e "production_rubylib" ]; then
+    if [[ -e "production_rubylib" ]]; then
         printf "brew-cask is already set up for development\n";
         exit 1
     else
diff --git a/developer/bin/production_brew_cask b/developer/bin/production_brew_cask
index 42729d097a..416de5be16 100755
--- a/developer/bin/production_brew_cask
+++ b/developer/bin/production_brew_cask
@@ -21,7 +21,7 @@ cd_to_project_root () {
 cd_to_version_dir () {
     local cellar_dir="$1"
     local version_dir="$2"
-    if [ -z "$version_dir" ]; then
+    if [[ -z "$version_dir" ]]; then
         printf "Can't get version dir under $cellar_dir/\n";
         exit 1;
     fi
@@ -30,13 +30,13 @@ cd_to_version_dir () {
 
 remove_dev_links () {
     local tap_dir="$1"
-    rm rubylib Casks
-    mv production_rubylib rubylib
-    mv production_Casks   Casks
+    /bin/rm rubylib Casks
+    /bin/mv production_rubylib rubylib
+    /bin/mv production_Casks   Casks
     cd "$tap_dir"
-    rm lib Casks
-    mv production_lib   lib
-    mv production_Casks Casks
+    /bin/rm lib Casks
+    /bin/mv production_lib   lib
+    /bin/mv production_Casks Casks
 }
 
 _production_brew_cask () {
@@ -46,21 +46,21 @@ _production_brew_cask () {
 
     # initialization
     cd_to_project_root;
-    local git_root=`pwd`
+    local git_root="$(pwd)"
     local brew_prefix="$(brew --prefix)"
     local cellar_dir="$brew_prefix/Cellar/brew-cask"
-    local version_dir=$(/bin/ls "$cellar_dir/" | sort | tail -1)
+    local version_dir="$(/bin/ls "$cellar_dir/" | /usr/bin/sort | /usr/bin/tail -1)"
     local tap_dir="$brew_prefix/$tap_subdir"
 
     # sanity check
-    if [[ $(/usr/bin/stat -L -f '%i' "$tap_dir") -eq $(/usr/bin/stat -L -f '%i' "$git_root") ]]; then
+    if [[ "$(/usr/bin/stat -L -f '%i' "$tap_dir")" -eq "$(/usr/bin/stat -L -f '%i' "$git_root")" ]]; then
         printf "\nERROR: run this script in your private repo, not inside Homebrew.\n"
         exit 1;
     fi
 
     # action
     cd_to_version_dir "$cellar_dir" "$version_dir";
-    if [ -e "production_rubylib" ]; then
+    if [[ -e "production_rubylib" ]]; then
         remove_dev_links "$tap_dir";
         printf "brew-cask is now in production mode\n"
         printf "It is safe to run 'brew update'\n"
diff --git a/developer/bin/project_stats b/developer/bin/project_stats
index ae5d8fb0e9..e01444ccb4 100755
--- a/developer/bin/project_stats
+++ b/developer/bin/project_stats
@@ -67,25 +67,25 @@ _homebrew_cask_project_stats () {
 
     local git_log_cmd="git log --no-merges --format='%ae' ${start_object}..${end_object}"
 
-    local cask_authors="$($git_log_cmd -- $cask_paths | sort | uniq | wc -l)"
+    local cask_authors="$($git_log_cmd -- $cask_paths | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l)"
     printf "  Casks\t$cask_authors\n"
     printf "  code\t"
-    $git_log_cmd -- $code_paths | sort | uniq | wc -l
+    $git_log_cmd -- $code_paths | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l
     printf "  docs\t"
-    $git_log_cmd -- $doc_paths  | sort | uniq | wc -l
+    $git_log_cmd -- $doc_paths  | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l
     printf "  any\t"
-    $git_log_cmd -- .           | sort | uniq | wc -l
+    $git_log_cmd -- .           | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l
     if [[ "$start_object" != "$initial_commit" ]]; then
         printf "\nAll-time contributors\t"
-        git log --no-merges --format='%ae' ${initial_commit}..${end_object} -- . | sort | uniq | wc -l
+        git log --no-merges --format='%ae' ${initial_commit}..${end_object} -- . | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l
     fi
 
     printf "\n"
 
     if [[ "$start_object" != "$initial_commit" ]]; then
-        local new_casks="$(git diff --name-status "$start_object" "$end_object" -- $cask_paths | /usr/bin/grep '^A.*\.rb' | cut -f2 | sort | uniq | wc -l)"
-        local deleted_casks="$(git diff --name-status "$start_object" "$end_object" -- $cask_paths | /usr/bin/grep '^D.*\.rb' | cut -f2 | sort | uniq | wc -l)"
-        local updated_casks="$(git diff --name-status "$start_object" "$end_object" -- $cask_paths | /usr/bin/grep '^M.*\.rb' | cut -f2 | sort | uniq | wc -l)"
+        local new_casks="$(git diff --name-status "$start_object" "$end_object" -- $cask_paths | /usr/bin/grep '^A.*\.rb' | cut -f2 | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l)"
+        local deleted_casks="$(git diff --name-status "$start_object" "$end_object" -- $cask_paths | /usr/bin/grep '^D.*\.rb' | cut -f2 | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l)"
+        local updated_casks="$(git diff --name-status "$start_object" "$end_object" -- $cask_paths | /usr/bin/grep '^M.*\.rb' | cut -f2 | /usr/bin/sort | /usr/bin/uniq | /usr/bin/wc -l)"
         # arithmetic removes whitespace
         ((cask_authors  += 0))
         ((deleted_casks += 0))
@@ -95,7 +95,7 @@ _homebrew_cask_project_stats () {
     fi
 
     printf "Total current Casks in HEAD\t"
-    find $cask_paths -name '*.rb' | wc -l
+    /usr/bin/find $cask_paths -name '*.rb' | /usr/bin/wc -l
 
 }