diff --git a/clean b/clean
index 13d64d5..b8cb48b 100755
--- a/clean
+++ b/clean
@@ -2,7 +2,7 @@
 day="$1"
 part="$2"
 
-day="$(printf '%02d' "$day")"
+day="$(printf '%02d' "${day##0}")"
 
 rm -f ./run
 rm -f "day${1}/part${2}.hi" "day${1}/part${2}.o"
diff --git a/prepare b/prepare
index 968aff7..c7fcbda 100755
--- a/prepare
+++ b/prepare
@@ -2,7 +2,7 @@
 day="$1"
 part="$2"
 
-day="$(printf '%02d' "$day")"
+day="$(printf '%02d' "${day##0}")"
 
 if test -f "day${day}/part${part}.lua"; then
 	/usr/bin/env luajit -v >/dev/null