diff --git a/BackupPC_archiveHost_s3 b/BackupPC_archiveHost_s3
index cfc1926..4872417 100755
--- a/BackupPC_archiveHost_s3
+++ b/BackupPC_archiveHost_s3
@@ -46,6 +46,9 @@ logger.addHandler(consolehandler)
 
 logger.setLevel(logging.DEBUG)
 
+class VerifyError(Exception):
+    pass
+
 def is_exe(fpath):
     return os.path.exists(fpath) and os.access(fpath, os.X_OK)
 
@@ -104,6 +107,7 @@ def verify_file(bucket, filename):
             fp = open(filename)
             local_md5 = hashlib.md5(fp.read())
             fp.close()
+            logger.debug("verify_file: %s: local md5 %s, etag %s", filename, local_md5.hexdigest(), key.etag)
             if '"%s"' % local_md5.hexdigest() == key.etag:
                 return True
     return False
@@ -120,6 +124,10 @@ def send_file(bucket, filename):
         logger.warning("send_file: %s already exists on S3, overwriting", basefilename)
 
     k.set_contents_from_filename(filename, cb=handle_progress, reduced_redundancy=True)
+
+    logger.debug("send_file: %s sent, verifying fidelity", filename)
+    if not verify_file(bucket, filename):
+        raise VerifyError("verify failed")
     return k
 
 def encryption_worker(in_q, out_q):
@@ -155,7 +163,7 @@ def sending_worker(in_q, out_q, accesskey, sharedkey, host):
                 key.set_acl('private')
                 key.close()
                 done = True
-            except (boto.exception.S3ResponseError, socket.error), e:
+            except (boto.exception.S3ResponseError, socket.error, VerifyError), e:
                 retry_count += 1
                 sleeptime = 2**retry_count
                 logger.error('sending_worker: exception %s, retrying in %i seconds (%i/%i)', e, sleeptime, retry_count, max_retries)
@@ -349,20 +357,34 @@ if __name__ == '__main__':
         gpg_queue.put('STOP')
 
     for i in procs:
+        # wait for each process to terminate in turn
         i.join()
+        logger.debug("main: process terminated: %s", i.name)
+
+        # count how many crypto processes are still running
         crypto_running = 0
         for j in procs:
             if j.name.startswith("encryption_worker") and j.is_alive():
                 crypto_running += 1
+
         if crypto_running == 0 and not send_queue_closed:
+            # crypto is done, close up the send queue
+            logger.debug("main: queuing final file")
+            finalfile = '%sCOMPLETE' % filehead
+            fp = open(finalfile, 'w')
+            fp.write('%s %s "%s"' % (beginning, time.time(), mesg))
+            fp.close()
+            send_queue.put(finalfile)
+
+            logger.debug("main: queuing stop sentinel for send_queue")
             send_queue.put('STOP')
             send_queue_closed = True
-            logger.debug("main: queuing stop sentinel for send_queue")
+
         if not send_p.is_alive() and not unlink_queue_closed:
+            # sending is done, close up the unlink queue
+            logger.debug("main: queuing stop sentinel for unlink_queue")
             unlink_queue.put('STOP')
             unlink_queue_closed = True
-            logger.debug("main: queuing stop sentinel for unlink_queue")
-        logger.debug("main: process terminated: %s", i.name)
 
     for qname, q in queues.items():
         time.sleep(5)  # settle
@@ -372,14 +394,4 @@ if __name__ == '__main__':
         else:
             logger.debug("main: queue %s is empty", qname)
 
-    logger.debug("main: finalizing backup")
-
-    # finalize the backup
-    bucket = open_s3(secrets.accesskey, secrets.sharedkey, host)
-    key = Key(bucket)
-    key.key = '%sCOMPLETE' % os.path.basename(filehead)
-    key.set_acl('private')
-    key.set_contents_from_string('%s %s "%s"' % (beginning, time.time(), mesg))
-    key.close()
-
     logger.info("main: completed run after %i seconds", (time.time() - beginning))