diff --git a/swh/model/tests/test_from_disk.py b/swh/model/tests/test_from_disk.py
--- a/swh/model/tests/test_from_disk.py
+++ b/swh/model/tests/test_from_disk.py
@@ -102,7 +102,6 @@
 
         self.specials = {
             b'fifo': os.mkfifo,
-            b'devnull': lambda path: os.mknod(path, device=os.makedev(1, 3)),
         }
 
         self.empty_content = {
@@ -507,22 +506,31 @@
         self.make_symlinks(self.tmpdir_name)
         self.make_specials(self.tmpdir_name)
 
-    def test_file_to_content(self):
+    def test_symlink_to_content(self):
         # Check whether loading the data works
         for data in [True, False]:
             for filename, symlink in self.symlinks.items():
                 path = os.path.join(self.tmpdir_name, filename)
-                conv_content = Content.from_file(path=path, data=data)
-                self.assertContentEqual(conv_content, symlink, check_data=data)
+                conv_content = Content.from_file(path=path)
+                self.assertContentEqual(conv_content, symlink)
 
+    def test_file_to_content(self):
+        for data in [True, False]:
             for filename, content in self.contents.items():
                 path = os.path.join(self.tmpdir_name, filename)
-                conv_content = Content.from_file(path=path, data=data)
-                self.assertContentEqual(conv_content, content, check_data=data)
+                conv_content = Content.from_file(path=path)
+                self.assertContentEqual(conv_content, content)
 
+    def test_special_to_content(self):
+        for data in [True, False]:
             for filename in self.specials:
                 path = os.path.join(self.tmpdir_name, filename)
-                conv_content = Content.from_file(path=path, data=data)
+                conv_content = Content.from_file(path=path)
+                self.assertContentEqual(conv_content, self.empty_content)
+
+            for path in ['/dev/null', '/dev/zero']:
+                path = os.path.join(self.tmpdir_name, filename)
+                conv_content = Content.from_file(path=path)
                 self.assertContentEqual(conv_content, self.empty_content)
 
     def test_symlink_max_length(self):