diff --git a/_modules/main_utils.py b/_modules/main_utils.py
index 91811076dd5701a327063814fecb3df5e6ab2c9c..db5cc7c5bf4ee5f0b215f41a258f576cd9271379 100755
--- a/_modules/main_utils.py
+++ b/_modules/main_utils.py
@@ -303,7 +303,7 @@ class InputDerivedDataArgs:
         length_virome = len("".join(self.refseq_liste))
         self.mean_virome = length_virome / self.nbr_virome
         if fparms.virome:
-            self.refseq_liste, self.refseq_name, refseq_rejected = ["N" * self.mean_virome], ["Test_virome"], 0
+            self.refseq_liste, self.refseq_name, refseq_rejected = ["N" * int(self.mean_virome)], ["Test_virome"], 0
         if len(self.refseq_liste) == 1 and inputRaw.host != "":
             self.hostseq = genomeFastaRecovery(inputRaw.host, fparms.limit_reference, fparms.edge, 1)
             if len(self.hostseq[0]) != 0 and len(self.hostseq[0]) > len(self.refseq_liste[0]):