diff --git a/chipathlon/jobs/scripts/download_fastq.py b/chipathlon/jobs/scripts/download_fastq.py
index 556b14e1ff8d85562dd3519e24d6ad381b32fa88..9b79b4b7cfb4f230aa339718d5d59d050f796e1b 100644
--- a/chipathlon/jobs/scripts/download_fastq.py
+++ b/chipathlon/jobs/scripts/download_fastq.py
@@ -7,7 +7,7 @@ parser.add_argument("-u", "--url", dest="url", required=True, help="Target url."
 parser.add_argument("-p", "--path", dest="path", required=True, help="Local path to file.")
 parser.add_argument("-t", "--url_type", dest="url_type", default="ftp://", help="Type of url to access.")
 parser.add_argument("-r", "--retries", dest="retries", default=3, type=int, help="Number of retries.")
-parser.add_argument("-o", "--overwrite", dest="overwrite", default=False, action="store_true", help="Overwrite local file if exists.")
+parser.add_argument("-n", "--overwrite", dest="overwrite", default=True, action="store_false", help="Dont' overwrite local file if exists.")
 parser.add_argument("-m", "--md5", dest="md5", help="Check md5 value against passed value.")
 args = parser.parse_args()
 
diff --git a/chipathlon/utils.py b/chipathlon/utils.py
index a0a93b65de8a2d2dc6b7cb3ff911a30493ba34b9..62152d3204d0668d5ef2f0b76f55279918bc7f74 100644
--- a/chipathlon/utils.py
+++ b/chipathlon/utils.py
@@ -13,7 +13,7 @@ def progress(current, end, length=20):
     sys.stdout.flush()
 
 
-def downloadFile(url, localpath, urltype="ftp://", retries=3, overwrite=False, checkmd5=False, md5=None):
+def downloadFile(url, localpath, urltype="ftp://", retries=3, overwrite=True, checkmd5=False, md5=None):
     success = False
     if url[:7] == "http://":
         urltype = ""
diff --git a/chipathlon/workflow.py b/chipathlon/workflow.py
index 6921c58cb37c2c18798f090f23bfe3da989249a8..c6c534c170a058d63863fe0e50f934bfe0f214c5 100644
--- a/chipathlon/workflow.py
+++ b/chipathlon/workflow.py
@@ -253,7 +253,7 @@ class Workflow(object):
                         self.files[output_name] = output_file
                         job = Job(self.executables["download_fastq.py"])
                         job.uses(output_file, link=Link.OUTPUT, transfer=True)
-                        job.addArguments("-u", f["url"], "-p", output_file, "-t http://", "-m", f["content_md5sum"])
+                        job.addArguments("-u", f["url"], "-p", output_file, "-t http://", "-m", f["md5sum"])
                         self.jobs[output_name] = job
                         self.dax.addJob(job)
         return