diff --git a/R/fuzznuc.sh b/R/fuzznuc.sh
index 3573d0b..e817a8b 100644
--- a/R/fuzznuc.sh
+++ b/R/fuzznuc.sh
@@ -39,7 +39,10 @@ echo "BED file created: ${output_base}.bed"
 
 # Generate sequence name and length table
 echo "Generating sequence name and length table..."
-awk 'BEGIN {OFS="\t"} /^>/ {if (seq) print id, length(seq); id=substr($1, 2); seq=""} !/^>/ {seq = seq $0} END {if (seq) print id, length(seq)}' "$genome" > "${output_base}_length.tsv"
+awk 'BEGIN {OFS="\t"}
+     /^>/ { if (len) print id, len; id=substr($1, 2); len=0 }
+     !/^>/ { len += length($0) }
+     END { if (len) print id, len }' "$genome" > "${output_base}_length.tsv"
 echo "Sequence name and length table created: ${output_base}_length.tsv"
 
 # Clean up intermediate files