diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 9ea30756f1..470413b9f9 100644
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -866,12 +866,12 @@ add_exec_commands () {
 # $3: the input filename
 check_commit_sha () {
 	badsha=0
-	if test -z $1
+	if test -z "$1"
 	then
 		badsha=1
 	else
 		sha1_verif="$(git rev-parse --verify --quiet $1^{commit})"
-		if test -z $sha1_verif
+		if test -z "$sha1_verif"
 		then
 			badsha=1
 		fi
diff --git a/git-stash.sh b/git-stash.sh
index c7c65e25f5..c7509e8da4 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -185,7 +185,7 @@ store_stash () {
 
 	git update-ref --create-reflog -m "$stash_msg" $ref_stash $w_commit
 	ret=$?
-	test $ret != 0 && test -z $quiet &&
+	test $ret != 0 && test -z "$quiet" &&
 	die "$(eval_gettext "Cannot update \$ref_stash with \$w_commit")"
 	return $ret
 }
@@ -277,7 +277,7 @@ save_stash () {
 			git clean --force --quiet -d $CLEAN_X_OPTION
 		fi
 
-		if test "$keep_index" = "t" && test -n $i_tree
+		if test "$keep_index" = "t" && test -n "$i_tree"
 		then
 			git read-tree --reset -u $i_tree
 		fi
diff --git a/t/t4151-am-abort.sh b/t/t4151-am-abort.sh
index ea5ace99a1..9473c2779e 100755
--- a/t/t4151-am-abort.sh
+++ b/t/t4151-am-abort.sh
@@ -82,7 +82,7 @@ test_expect_success 'am -3 --abort removes otherfile-4' '
 	test 4 = "$(cat otherfile-4)" &&
 	git am --abort &&
 	test_cmp_rev initial HEAD &&
-	test -z $(git ls-files -u) &&
+	test -z "$(git ls-files -u)" &&
 	test_path_is_missing otherfile-4
 '