diff --git a/dockerfiles/docker-myeloseq/filterHaloplex.py b/dockerfiles/docker-myeloseq/filterHaloplex.py
index 6a4a3e8..3a6ee93 100644
--- a/dockerfiles/docker-myeloseq/filterHaloplex.py
+++ b/dockerfiles/docker-myeloseq/filterHaloplex.py
@@ -503,7 +503,12 @@ def revcomp(seq):
 
             ro = rec.samples[0]['AD'][0]
             ao = rec.samples[0]['AD'][1]
-            rawvaf = round(ao / (ao + ro),4) #rec.samples[0]['AF'][0]
+
+            if ao + ro == 0:
+                rawvaf = 0
+            else:
+                rawvaf = round(ao / (ao + ro),4) #rec.samples[0]['AF'][0]
+
             for v in rec.filter.keys():
                 nrec.filter.add(v)