diff --git a/src/tufup/common.py b/src/tufup/common.py
index 6ecb19a..5ca2b61 100644
--- a/src/tufup/common.py
+++ b/src/tufup/common.py
@@ -203,14 +203,12 @@ def diff_and_hash(
 
         Returns a dict with size and hash of the *uncompressed* destination archive.
         """
-        with (
-            gzip.open(src_path, mode='rb') as src_file,
-            gzip.open(dst_path, mode='rb') as dst_file,
-        ):
-            dst_tar_content = dst_file.read()
-            patch_path.write_bytes(
-                bsdiff4.diff(src_bytes=src_file.read(), dst_bytes=dst_tar_content)
-            )
+        with gzip.open(src_path, mode='rb') as src_file:
+            with gzip.open(dst_path, mode='rb') as dst_file:
+                dst_tar_content = dst_file.read()
+                patch_path.write_bytes(
+                    bsdiff4.diff(src_bytes=src_file.read(), dst_bytes=dst_tar_content)
+                )
         return cls._get_tar_size_and_hash(tar_content=dst_tar_content)
 
     @classmethod
diff --git a/tests/test_common.py b/tests/test_common.py
index 4c65d83..e4d99fb 100644
--- a/tests/test_common.py
+++ b/tests/test_common.py
@@ -232,8 +232,6 @@ def test_patch_and_verify(self):
         self.assertTrue(dst_path.exists())
         # note that gzip compressed files are not reproducible by default (even when
         # using identical uncompressed data), so we must compare the uncompressed data
-        with (
-            gzip.open(self.targz_paths[dst], mode='rb') as original_tar,
-            gzip.open(dst_path, mode='rb') as reconstructed_tar,
-        ):
-            self.assertEqual(original_tar.read(), reconstructed_tar.read())
+        with gzip.open(self.targz_paths[dst], mode='rb') as original_tar:
+            with gzip.open(dst_path, mode='rb') as reconstructed_tar:
+                self.assertEqual(original_tar.read(), reconstructed_tar.read())