diff --git a/snakecnv/bin/filter.py b/snakecnv/bin/filter.py
index 099fbeed73c72b38ca912da3c4d5d28dc459aec2..9f3f7a0959975e198f4675da68e5f0c74370e874 100755
--- a/snakecnv/bin/filter.py
+++ b/snakecnv/bin/filter.py
@@ -96,7 +96,8 @@ def UnifiedPassAnnotation(SVSet):
         filters = [f for f in record.filter]
         # We make the assumption when a "." is present no other filter
         # are present
-        if "." in filters:
+        # if no filter or "." is present in filters
+        if len(filters) == 0 or "." in filters:
             record.filter.clear()
             record.filter.add("PASS")