diff --git a/workflow/envs/env.yaml b/workflow/envs/env.yaml
index d2aa52b..afe87b2 100644
--- a/workflow/envs/env.yaml
+++ b/workflow/envs/env.yaml
@@ -12,7 +12,7 @@ dependencies:
   - bedtools
   - samtools>=1.9
   - pysam
-  - snakemake>=7.8
+  - snakemake>=7.25.0
   - snakefmt
   - bwa
   - pigz 
diff --git a/workflow/scripts/ntn_bam_to_contacts.py b/workflow/scripts/ntn_bam_to_contacts.py
index f668949..5e26b29 100755
--- a/workflow/scripts/ntn_bam_to_contacts.py
+++ b/workflow/scripts/ntn_bam_to_contacts.py
@@ -100,7 +100,7 @@ def main():
                     # print('extra field:', extra_field, file=sys.stderr)
                     alignments += parse_extra_alignments(extra_field)
 
-            for (mapped_seq, mapped_pos) in alignments:
+            for mapped_seq, mapped_pos in alignments:
                 print(
                     "{}\t{}\t{}\t{}\t{}\t{}\t1".format(
                         original_location[0],