diff --git a/test.sh b/test.sh
index 6b5c8a1..baa9cf5 100755
--- a/test.sh
+++ b/test.sh
@@ -4,9 +4,11 @@ set -euo pipefail
 
 cd "$(dirname "${BASH_SOURCE[0]}")"
 
-YEAR=2020
+COMMON_DIR="$(realpath common)"
+export COMMON_DIR
 
-export COMMON_DIR="$(realpath common)"
+OUTDIR=$(mktemp --directory)
+trap "rm -rf '$OUTDIR'" EXIT
 
 run_solution() {
 	if [ -d "$solution" ]; then
@@ -33,13 +35,14 @@ run_solution() {
 	fi
 }
 
-shopt -s dotglob nullglob
+do_day() {
+	year=$1
+	day=$2
 
-for n in $(seq 1 25); do
-	input=$YEAR/data/day$n.input
-	expected=$YEAR/data/day$n.expected
+	input=$year/data/day$day.input
+	expected=$year/data/day$day.expected
 
-	for solution in "$YEAR/day$n"/*; do
+	for solution in "$year/day$day"/*; do
 		echo -n "$solution... "
 
 		case "${solution##*/}" in
@@ -48,9 +51,7 @@ for n in $(seq 1 25); do
 				continue
 		esac
 
-		solution_output=$(mktemp)
-		trap "rm -f '$solution_output'" EXIT
-
+		solution_output=$OUTDIR/${year}_$day.out
 		run_solution "$solution" > "$solution_output"
 
 		if ! diff -u "$expected" "$solution_output"; then
@@ -67,7 +68,19 @@ for n in $(seq 1 25); do
 		else
 			echo ok
 		fi
-
-		rm "$solution_output"
 	done
+}
+
+do_year() {
+	year=$1
+
+	for day in $(seq 1 25); do
+		do_day "$year" "$day"
+	done
+}
+
+shopt -s dotglob nullglob
+
+for year in 2020 2021 2022; do
+	do_year "$year"
 done