diff --git a/src/repertoire.r b/src/repertoire.r
index 23ab344..0cb40b8 100644
--- a/src/repertoire.r
+++ b/src/repertoire.r
@@ -14,9 +14,9 @@ amplify_rows <- function(data, column, factor) {
   if (column == "sequence") {
     dna_string <- Biostrings::DNAStringSet(data)
     reverse_complement <- Biostrings::reverseComplement(dna_string)
-    return(Biostrings::DNAStringSet(rep(reverse_complement, factor)))
+    return(rep(reverse_complement, factor))
   }
-  return(as.character(rep(data, factor)))
+  return(rep(data, factor))
 }
 
 save_data <- function(data, name) {