diff --git a/test/lint/git-subtree-check.sh b/test/lint/git-subtree-check.sh
index 2384d66cad..9f34451e1a 100755
--- a/test/lint/git-subtree-check.sh
+++ b/test/lint/git-subtree-check.sh
@@ -1,77 +1,77 @@
 #!/bin/sh
 # Copyright (c) 2015 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 DIR="$1"
 COMMIT="$2"
 if [ -z "$COMMIT" ]; then
     COMMIT=HEAD
 fi
 
 # Taken from git-subtree (Copyright (C) 2009 Avery Pennarun <apenwarr@gmail.com>)
 find_latest_squash()
 {
 	dir="$1"
 	sq=
 	main=
 	sub=
 	git log --grep="^git-subtree-dir: $dir/*\$" \
 		--pretty=format:'START %H%n%s%n%n%b%nEND%n' "$COMMIT" |
-	while read a b junk; do
+	while read a b _; do
 		case "$a" in
 			START) sq="$b" ;;
 			git-subtree-mainline:) main="$b" ;;
 			git-subtree-split:) sub="$b" ;;
 			END)
 				if [ -n "$sub" ]; then
 					if [ -n "$main" ]; then
 						# a rejoin commit?
 						# Pretend its sub was a squash.
 						sq="$sub"
 					fi
 					echo "$sq" "$sub"
 					break
 				fi
 				sq=
 				main=
 				sub=
 				;;
 		esac
 	done
 }
 
 latest_squash="$(find_latest_squash "$DIR")"
 if [ -z "$latest_squash" ]; then
     echo "ERROR: $DIR is not a subtree" >&2
     exit 2
 fi
 
 set $latest_squash
 old=$1
 rev=$2
 if [ "d$(git cat-file -t $rev 2>/dev/null)" != dcommit ]; then
     echo "ERROR: subtree commit $rev unavailable. Fetch/update the subtree repository" >&2
     exit 2
 fi
 tree_subtree=$(git show -s --format="%T" $rev)
 echo "$DIR in $COMMIT was last updated to upstream commit $rev (tree $tree_subtree)"
 tree_actual=$(git ls-tree -d "$COMMIT" "$DIR" | head -n 1)
 if [ -z "$tree_actual" ]; then
     echo "FAIL: subtree directory $DIR not found in $COMMIT" >&2
     exit 1
 fi
 set $tree_actual
 tree_actual_type=$2
 tree_actual_tree=$3
 echo "$DIR in $COMMIT currently refers to $tree_actual_type $tree_actual_tree"
 if [ "d$tree_actual_type" != "dtree" ]; then
     echo "FAIL: subtree directory $DIR is not a tree in $COMMIT" >&2
     exit 1
 fi
 if [ "$tree_actual_tree" != "$tree_subtree" ]; then
     git diff-tree $tree_actual_tree $tree_subtree >&2
     echo "FAIL: subtree directory tree doesn't match subtree commit tree" >&2
     exit 1
 fi
 echo "GOOD"