diff --git a/pre_processing.py b/pre_processing.py
index 7df576b019b22dce0b872e0c8435608e619038fa..936c3c6d7930de8ff61284ef194415dbd76a56d1 100755
--- a/pre_processing.py
+++ b/pre_processing.py
@@ -194,7 +194,7 @@ def convert_to_sequence(compressed_dir_path, payload_fragments_dir_path):
         # checking if it is a file
         if os.path.isfile(file_path):
             
-            output_file_path = os.path.join(payload_fragments_dir_path, filename.replace(".gz", ".fasta"))
+            output_file_path = os.path.join(payload_fragments_dir_path, filename.replace(".gz", ""))
 
             dna_sequence = file_to_dna.encode_file(file_path, output_file_path) # convert binaries into a dna sequence and save result in the output file