diff --git a/Documents/Shore/taxes/Makefile b/Documents/Shore/taxes/Makefile
index afc3a7cd7c70dc9fd092aeb1952fcc7c4ed6823a..08130cbbc6f8fae164b99c1ac487d173dc9e2d81 100644
--- a/Documents/Shore/taxes/Makefile
+++ b/Documents/Shore/taxes/Makefile
@@ -1,5 +1,5 @@
 last_month != date +%Y-%m --date 'last month'
-last_zip != ls *.zip | sort -r | head -1
+last_zip != find -maxdepth 1 -name '*.zip' \! -name '${last_month}.zip' -printf '%f\n' | sort -r | head -1
 new_files != find reciepts/ -type f -newer ${last_zip}
 
 ${last_month}.zip: ${new_files}