diff --git a/swh/model/hypothesis_strategies.py b/swh/model/hypothesis_strategies.py
--- a/swh/model/hypothesis_strategies.py
+++ b/swh/model/hypothesis_strategies.py
@@ -215,7 +215,7 @@
     target = sha1_git()
     metadata = optional(revision_metadata())
 
-    return draw(
+    d = draw(
         one_of(
             builds(
                 dict,
@@ -242,6 +242,11 @@
         )
     )
 
+    raw_manifest = draw(optional(binary()))
+    if raw_manifest:
+        d["raw_manifest"] = raw_manifest
+    return d
+
 
 def releases():
     return releases_d().map(Release.from_dict)
@@ -256,23 +261,31 @@
     ).map(tuple)
 
 
-def revisions_d():
-    return builds(
-        dict,
-        message=optional(binary()),
-        synthetic=booleans(),
-        author=persons_d(),
-        committer=persons_d(),
-        date=timestamps_with_timezone_d(),
-        committer_date=timestamps_with_timezone_d(),
-        parents=tuples(sha1_git()),
-        directory=sha1_git(),
-        type=sampled_from([x.value for x in RevisionType]),
-        metadata=optional(revision_metadata()),
-        extra_headers=extra_headers(),
+@composite
+def revisions_d(draw):
+    d = draw(
+        builds(
+            dict,
+            message=optional(binary()),
+            synthetic=booleans(),
+            author=persons_d(),
+            committer=persons_d(),
+            date=timestamps_with_timezone_d(),
+            committer_date=timestamps_with_timezone_d(),
+            parents=tuples(sha1_git()),
+            directory=sha1_git(),
+            type=sampled_from([x.value for x in RevisionType]),
+            metadata=optional(revision_metadata()),
+            extra_headers=extra_headers(),
+        )
     )
     # TODO: metadata['extra_headers'] can have binary keys and values
 
+    raw_manifest = draw(optional(binary()))
+    if raw_manifest:
+        d["raw_manifest"] = raw_manifest
+    return d
+
 
 def revisions():
     return revisions_d().map(Revision.from_dict)
@@ -316,8 +329,14 @@
     return directory_entries_d().map(DirectoryEntry)
 
 
-def directories_d():
-    return builds(dict, entries=tuples(directory_entries_d()))
+@composite
+def directories_d(draw):
+    d = draw(builds(dict, entries=tuples(directory_entries_d())))
+
+    raw_manifest = draw(optional(binary()))
+    if raw_manifest:
+        d["raw_manifest"] = raw_manifest
+    return d
 
 
 def directories():
diff --git a/swh/model/tests/test_model.py b/swh/model/tests/test_model.py
--- a/swh/model/tests/test_model.py
+++ b/swh/model/tests/test_model.py
@@ -753,7 +753,7 @@
 # Directory
 
 
-@given(strategies.directories())
+@given(strategies.directories().filter(lambda d: d.raw_manifest is None))
 def test_directory_check(directory):
     directory.check()
 
@@ -770,7 +770,7 @@
         directory2.check()
 
 
-@given(strategies.directories())
+@given(strategies.directories().filter(lambda d: d.raw_manifest is None))
 def test_directory_raw_manifest(directory):
     assert "raw_manifest" not in directory.to_dict()
 
@@ -813,7 +813,7 @@
 # Release
 
 
-@given(strategies.releases())
+@given(strategies.releases().filter(lambda rel: rel.raw_manifest is None))
 def test_release_check(release):
     release.check()
 
@@ -830,10 +830,8 @@
         release2.check()
 
 
-@given(strategies.releases())
+@given(strategies.releases().filter(lambda rev: rev.raw_manifest is None))
 def test_release_raw_manifest(release):
-    assert "raw_manifest" not in release.to_dict()
-
     raw_manifest = b"foo"
     id_ = hashlib.new("sha1", raw_manifest).digest()
 
@@ -852,7 +850,7 @@
 # Revision
 
 
-@given(strategies.revisions())
+@given(strategies.revisions().filter(lambda rev: rev.raw_manifest is None))
 def test_revision_check(revision):
     revision.check()
 
@@ -869,9 +867,8 @@
         revision2.check()
 
 
-@given(strategies.revisions())
+@given(strategies.revisions().filter(lambda rev: rev.raw_manifest is None))
 def test_revision_raw_manifest(revision):
-    assert "raw_manifest" not in revision.to_dict()
 
     raw_manifest = b"foo"
     id_ = hashlib.new("sha1", raw_manifest).digest()