diff --git a/ui/medashare/btv/__init__.py b/ui/medashare/btv/__init__.py
index f2c80dc..8ce2a29 100644
--- a/ui/medashare/btv/__init__.py
+++ b/ui/medashare/btv/__init__.py
@@ -275,20 +275,21 @@ def validate(torrent, basedir, with_file_hashes=None):
 
 			futures[fut] = num, hash, i
 
-		for i in range(min(len(pending_work), os.cpu_count() + 1)):
+		for i in range(min(len(pending_work), os.cpu_count() + 2)):
 			submit_work(*pending_work.pop(0))
 
-		for future in concurrent.futures.as_completed(futures):
-			if pending_work:
-				submit_work(*pending_work.pop(0))
+		while futures:
+			for future in concurrent.futures.as_completed(futures):
+				if pending_work:
+					submit_work(*pending_work.pop(0))
 
-			future.result()
-			num, hash, i = futures[future]
+				future.result()
+				num, hash, i = futures.pop(future)
 
-			if hash.digest() == i:
-				valid[num] = True
-			else:
-				valid[num] = False
+				if hash.digest() == i:
+					valid[num] = True
+				else:
+					valid[num] = False
 
 	if files is None:
 		filesizes = { pathlib.PurePosixPath(info['name'].decode(
@@ -448,7 +449,8 @@ class _TestCases(unittest.TestCase):
 			    list(origrglob(pathlib.PosixPath('.'), 'somedir'))
 
 		with unittest.mock.patch.object(pathlib.PosixPath, 'rglob',
-		    side_effect=_rglob_patch):
+		    side_effect=_rglob_patch), unittest.mock.patch.object(os,
+		    'cpu_count', side_effect=lambda: 3):
 			good, bad = validate_file(tf)
 
 		self.assertFalse(bad)
@@ -512,7 +514,7 @@ class _TestCases(unittest.TestCase):
 		with open(sd / '40plus1.txt', 'w') as fp:
 			fp.write('w')
 
-		good, bad, hashes = validate_file(tor, with_file_hashes=sha512)
+			good, bad, hashes = validate_file(tor, with_file_hashes=sha512)
 
 		self.assertEqual(bad, { sd / '40plus1.txt' })
 		self.assertFalse(good)