diff --git a/src/progress.sh b/src/progress.sh
index fd64f41..8080156 100644
--- a/src/progress.sh
+++ b/src/progress.sh
@@ -23,6 +23,7 @@ fi
 
 cluster=$(stat -f "$path" | grep -m 1 "^Block size:" | cut -d':' -f2 | tail -c+2 | cut -d' ' -f1)
 total=$(( ( ( total + cluster / 2 ) / cluster ) * cluster ))
+[ -z "$total" ] && total="4096"
 
 while true
 do