diff --git a/completions/django.completion.sh b/completions/django.completion.sh
index 7101607..0170e50 100644
--- a/completions/django.completion.sh
+++ b/completions/django.completion.sh
@@ -43,10 +43,10 @@ complete -F _django_completion -o default django-admin.py manage.py django-admin
 _python_django_completion()
 {
     if [[ ${COMP_CWORD} -ge 2 ]]; then
-        PYTHON_EXE=$( basename -- ${COMP_WORDS[0]} )
+        PYTHON_EXE=$( basename -- "${COMP_WORDS[0]}" )
         echo $PYTHON_EXE | command grep -E "python([2-9]\.[0-9])?" >/dev/null 2>&1
         if [[ $? == 0 ]]; then
-            PYTHON_SCRIPT=$( basename -- ${COMP_WORDS[1]} )
+            PYTHON_SCRIPT=$( basename -- "${COMP_WORDS[1]}" )
             echo $PYTHON_SCRIPT | command grep -E "manage\.py|django-admin(\.py)?" >/dev/null 2>&1
             if [[ $? == 0 ]]; then
                 COMPREPLY=( $( COMP_WORDS="${COMP_WORDS[*]:1}" \
@@ -58,16 +58,16 @@ _python_django_completion()
 }
 
 # Support for multiple interpreters.
-unset pythons
+unset -v pythons
 if _omb_util_command_exists whereis; then
-    python_interpreters=$(whereis python | cut -d " " -f 2-)
-    for python in $python_interpreters; do
-        pythons="${pythons} $(basename -- $python)"
+    _omb_util_split python_interpreters "$(whereis python | cut -d " " -f 2-)"
+    pythons=()
+    for python in "${python_interpreters[@]}"; do
+        pythons+=("$(basename -- "$python")")
     done
-    pythons=$(echo $pythons | tr " " "\n" | sort -u | tr "\n" " ")
+    pythons=($(printf '%s\n' "${pythons[@]}" | sort -u))
 else
-    pythons=python
+    pythons=(python)
 fi
 
-complete -F _python_django_completion -o default $pythons
-
+complete -F _python_django_completion -o default "${pythons[@]}"
diff --git a/completions/gh.completion.sh b/completions/gh.completion.sh
index 175fda4..463b922 100644
--- a/completions/gh.completion.sh
+++ b/completions/gh.completion.sh
@@ -200,7 +200,7 @@ EOF
       ((c++))
     done
     if [ -z "$name" ]; then
-      repo=$(basename "$(pwd)")
+      repo=$(basename "$PWD")
     fi
     case "$prev" in
       -d|-h)
diff --git a/completions/hub.completion.sh b/completions/hub.completion.sh
index 7c76bde..034265e 100644
--- a/completions/hub.completion.sh
+++ b/completions/hub.completion.sh
@@ -202,7 +202,7 @@ EOF
       ((c++))
     done
     if [ -z "$name" ]; then
-      repo=$(basename "$(pwd)")
+      repo=$(basename "$PWD")
     fi
     case "$prev" in
       -d|-h)
diff --git a/completions/vagrant.completion.sh b/completions/vagrant.completion.sh
index 9368738..51652b9 100644
--- a/completions/vagrant.completion.sh
+++ b/completions/vagrant.completion.sh
@@ -83,9 +83,9 @@ function _vagrant {
                 vagrant_state_file=$(__vagrantinvestigate) || return 1
                 if [[ -f $vagrant_state_file ]]
                 then
-                      running_vm_list=$(grep 'active' $vagrant_state_file | sed -e 's/"active"://' | tr ',' '\n' | cut -d '"' -f 2 | tr '\n' ' ')
+                      running_vm_list=$(grep 'active' "$vagrant_state_file" | sed -e 's/"active"://' | tr ',' '\n' | cut -d '"' -f 2 | tr '\n' ' ')
                 else
-                      running_vm_list=$(find $vagrant_state_file -type f -name "id" | awk -F"/" '{print $(NF-2)}')
+                      running_vm_list=$(find "$vagrant_state_file" -type f -name "id" | awk -F"/" '{print $(NF-2)}')
                 fi
                 COMPREPLY=($(compgen -W "${running_vm_list}" -- ${cur}))
                 return 0
diff --git a/completions/vault.completion.sh b/completions/vault.completion.sh
index e1a540a..02ec76f 100644
--- a/completions/vault.completion.sh
+++ b/completions/vault.completion.sh
@@ -32,7 +32,7 @@ function _vault() {
   if [[ $prev =~ ^(policies|policy-write|policy-delete) ]]; then
     local policies=$(vault policies 2> /dev/null)
     COMPREPLY=($(compgen -W "$policies" -- $cur))
-  elif [ "$(echo $line | wc -w)" -le 2 ]; then
+  elif [ "$(echo "$line" | wc -w)" -le 2 ]; then
     if [[ "$line" =~ ^vault\ (read|write|delete|list)\ $ ]]; then
       COMPREPLY=($(compgen -W "$(_vault_mounts)" -- ''))
     else
diff --git a/lib/omb-prompt-base.sh b/lib/omb-prompt-base.sh
index f79d682..40e937f 100644
--- a/lib/omb-prompt-base.sh
+++ b/lib/omb-prompt-base.sh
@@ -244,7 +244,7 @@ function git_prompt_vars {
                           command git status --porcelain ${git_status_flags}    2> /dev/null) | git_status_summary)
     local status=$(awk 'NR==1' <<< "$status_lines")
     local counts=$(awk 'NR==2' <<< "$status_lines")
-    IFS=$'\t' read untracked_count unstaged_count staged_count <<< "$counts"
+    IFS=$'\t' read -r untracked_count unstaged_count staged_count <<< "$counts"
     if [[ "${untracked_count}" -gt 0 || "${unstaged_count}" -gt 0 || "${staged_count}" -gt 0 ]]; then
       SCM_DIRTY=1
       if [[ "${SCM_GIT_SHOW_DETAILS}" = "true" ]]; then
@@ -341,7 +341,7 @@ function svn_prompt_vars {
 # - .hg is located in ~/Projects/Foo/.hg
 # - get_hg_root starts at ~/Projects/Foo/Bar and sees that there is no .hg directory, so then it goes into ~/Projects/Foo
 function get_hg_root {
-    local CURRENT_DIR=$(pwd)
+    local CURRENT_DIR=$PWD
 
     while [ "$CURRENT_DIR" != "/" ]; do
         if [ -d "$CURRENT_DIR/.hg" ]; then
@@ -349,7 +349,7 @@ function get_hg_root {
             return
         fi
 
-        CURRENT_DIR=$(dirname $CURRENT_DIR)
+        CURRENT_DIR=$(dirname "$CURRENT_DIR")
     done
 }
 
diff --git a/lib/readlink.sh b/lib/readlink.sh
index 46f1f65..98373a9 100644
--- a/lib/readlink.sh
+++ b/lib/readlink.sh
@@ -87,6 +87,7 @@ function _omb_util_readlink__resolve {
     readlink=$(type -P readlink)
     case $readlink in
     (/bin/readlink | /usr/bin/readlink)
+      # shellcheck disable=SC2100
       _omb_util_readlink_type=readlink-f
       function _omb_util_readlink__resolve { readlink -f -- "$1"; } ;;
     esac ;;
diff --git a/lib/utils.sh b/lib/utils.sh
index 6fcee39..eca8c7e 100644
--- a/lib/utils.sh
+++ b/lib/utils.sh
@@ -243,7 +243,7 @@ function _omb_log_note      { printf "${_omb_term_underline}${_omb_term_bold}${_
 #
 function seek_confirmation {
   printf "\\n${_omb_term_bold}%s${_omb_term_reset}" "$@"
-  read -p " (y/n) " -n 1
+  read -rp " (y/n) " -n 1
   printf "\\n"
 }
 
@@ -309,6 +309,7 @@ function _omb_util_unload {
 }
 
 _omb_util_original_PS1=$PS1
+# shellcheck disable=SC2016
 _omb_util_unload_hook+=('PS1=$_omb_util_original_PS1')
 
 _omb_util_prompt_command=()
diff --git a/themes/agnoster/agnoster.theme.sh b/themes/agnoster/agnoster.theme.sh
index 81fe114..cf5eaa8 100644
--- a/themes/agnoster/agnoster.theme.sh
+++ b/themes/agnoster/agnoster.theme.sh
@@ -107,7 +107,7 @@
 # export THEME=$HOME/.bash/themes/agnoster-bash/agnoster.bash
 # if [[ -f $THEME ]]; then
 #     export DEFAULT_USER=$(whoami)
-#     source $THEME
+#     source "$THEME"
 # fi
 
 #
diff --git a/themes/duru/duru.theme.sh b/themes/duru/duru.theme.sh
index a968c2b..a8a485c 100644
--- a/themes/duru/duru.theme.sh
+++ b/themes/duru/duru.theme.sh
@@ -6,7 +6,7 @@ SCM_THEME_PROMPT_DIRTY=" ${_omb_prompt_brown}with changes"
 SCM_THEME_PROMPT_CLEAN=""
 
 function venv {
-  if [ ! -z "$VIRTUAL_ENV" ]
+  if [ -n "$VIRTUAL_ENV" ]
   then
     local env=$VIRTUAL_ENV
     echo "${gray} in ${_omb_prompt_red}${env##*/} "
@@ -14,7 +14,7 @@ function venv {
 }
 
 function last_two_dirs {
-  pwd|rev|awk -F / '{print $1,$2}'|rev|sed s_\ _/_|sed "s|$(sed 's,\/,,'<<<$HOME)|~|g"
+  pwd|rev|awk -F / '{print $1,$2}'|rev|sed s_\ _/_|sed "s|$(sed 's,\/,,'<<<"$HOME")|~|g"
 }
 
 function _omb_theme_PROMPT_COMMAND {
diff --git a/themes/hawaii50/hawaii50.theme.sh b/themes/hawaii50/hawaii50.theme.sh
index 7007d8b..768e9da 100644
--- a/themes/hawaii50/hawaii50.theme.sh
+++ b/themes/hawaii50/hawaii50.theme.sh
@@ -169,7 +169,7 @@ function limited_pwd() {
     # Replace $HOME with ~ if possible 
     local RELATIVE_PWD=${PWD/#$HOME/\~}
 
-    local offset=$((${#RELATIVE_PWD}-$MAX_PWD_LENGTH))
+    local offset=$((${#RELATIVE_PWD}-MAX_PWD_LENGTH))
 
     if ((offset > 0)); then
         local truncated_symbol="..."