diff --git a/backup.sh b/backup.sh
index 6db5a7b..401d468 100755
--- a/backup.sh
+++ b/backup.sh
@@ -194,7 +194,7 @@ delete-thinning () {
 
   # Warn if $MAX_BACKUPS does not have enough room for all the blocks
   TOTAL_BLOCK_SIZE=$(array-sum ${BLOCK_SIZES[@]})
-  if [[ $TOTAL_BLOCK_SIZE -gt $MAX_BACKUPS ]]; then
+  if [[  $MAX_BACKUPS != -1 ]] && [[ $TOTAL_BLOCK_SIZE -gt $MAX_BACKUPS ]]; then
     if ! $SUPPRESS_WARNINGS; then
       log-warning "MAX_BACKUPS ($MAX_BACKUPS) is smaller than TOTAL_BLOCK_SIZE ($TOTAL_BLOCK_SIZE)"
     fi