diff --git a/nextnumber b/nextnumber
index 6b91a92..f70ec50 100755
--- a/nextnumber
+++ b/nextnumber
@@ -1,13 +1,18 @@
 #!/usr/bin/env bash
 # TODO: Find a less trashy way to get the next available error code
-if ! shopt -s globstar
-then
+if ! shopt -s globstar; then
   echo "Error: This script depends on Bash 4." >&2
   exit 1
 fi
 
-for i in 1 2
-do
-  last=$(grep -hv "^prop" ./**/*.hs | grep -Ewo "$i[0-9]{3}" | sort -n | tail -n 1)
+for i in 1 2; do
+  last=$(grep --no-filename --invert-match "^prop" ./**/*.hs \
+	| grep --extended-regexp --word-regexp --only-matching "$i[0-9]{3}" \
+	| sort --numeric-sort \
+	| tail --lines 1
+)
   echo "Next ${i}xxx: $((last+1))"
 done
+
+exit 0
+
diff --git a/quickrun b/quickrun
index 4bdf8eb..67d1d92 100755
--- a/quickrun
+++ b/quickrun
@@ -1,5 +1,7 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # quickrun runs ShellCheck in an interpreted mode.
 # This allows testing changes without recompiling.
 
 runghc -isrc -idist/build/autogen shellcheck.hs "$@"
+
+exit
\ No newline at end of file
diff --git a/quicktest b/quicktest
index f4ed0b3..0654189 100755
--- a/quicktest
+++ b/quicktest
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 # quicktest runs the ShellCheck unit tests in an interpreted mode.
 # This allows running tests without compiling, which can be faster.
 # 'cabal test' remains the source of truth.
@@ -16,7 +16,7 @@ if [[ $var == *$'\nTrue'* ]]
 then
   exit 0
 else
-  grep -C 3 -e "Fail" -e "Tracing" <<< "$var"
+  grep --context 3 --regexp "Fail" --regexp "Tracing" <<< "${var}"
   exit 1
 fi
 ) 2>&1
diff --git a/striptests b/striptests
index 78c5220..679068f 100755
--- a/striptests
+++ b/striptests
@@ -5,15 +5,14 @@
 set -o pipefail
 
 sponge() {
-  data="$(cat)"
-  printf '%s\n' "$data" > "$1"
+  local -r DATA="$(cat)"
+  printf '%s\n' "${DATA}" > "${1}"
 }
 
 modify() {
-  if ! "${@:2}" < "$1" | sponge "$1"
-  then
+  if ! "${@:2}" < "${1}" | sponge "${1}"
     {
-      printf 'Failed to modify %s: ' "$1"
+      printf 'Failed to modify %s: ' "${1}"
       printf '%q ' "${@:2}"
       printf '\n'
     } >&2
@@ -50,28 +49,23 @@ detestify() {
     '
 }
 
-
-
-if [[ ! -e ShellCheck.cabal ]]
-then
+if [[ ! -e 'ShellCheck.cabal' ]]; then
   echo "Run me from the ShellCheck directory." >&2
   exit 1
 fi
 
-if [[ -d '.git' ]] && ! git diff --exit-code > /dev/null 2>&1
-then
+if [[ -d '.git' ]] && ! git diff --exit-code > /dev/null 2>&1; then
   echo "You have local changes! These may be overwritten." >&2
   exit 2
 fi
 
-modify ShellCheck.cabal sed -e '
+modify 'ShellCheck.cabal' sed -e '
   /QuickCheck/d
   /^test-suite/{ s/.*//; q; }
   '
 
-find . -name '.git' -prune -o -type f -name '*.hs' -print |
-  while IFS= read -r file
-  do
-    modify "$file" detestify
-  done
+while IFS= read -r file; do
+  modify "${file}" detestify
+done < <(find . -name '.git' -prune -o -type f -name '*.hs' -print)
 
+exit 0