diff --git a/dvc/repo/__init__.py b/dvc/repo/__init__.py
index 863979c69..61ed75150 100644
--- a/dvc/repo/__init__.py
+++ b/dvc/repo/__init__.py
@@ -141,6 +141,7 @@ class Repo:
         from dvc.repo.params import Params
         from dvc.repo.plots import Plots
         from dvc.repo.stage import StageLoad
+        from dvc.scm import SCM
         from dvc.stage.cache import StageCache
         from dvc.state import State, StateNoop
 
@@ -149,6 +150,9 @@ class Repo:
             "repo_factory": repo_factory,
         }
 
+        if rev and not scm:
+            scm = SCM(root_dir or os.curdir)
+
         self.root_dir, self.dvc_dir, self.tmp_dir = self._get_repo_dirs(
             root_dir=root_dir, scm=scm, rev=rev, uninitialized=uninitialized
         )
diff --git a/tests/func/test_api.py b/tests/func/test_api.py
index 6050e1a39..79bc900ff 100644
--- a/tests/func/test_api.py
+++ b/tests/func/test_api.py
@@ -182,6 +182,15 @@ def test_open_not_cached(dvc):
         api.read(metric_file)
 
 
+def test_open_rev(tmp_dir, scm, dvc):
+    tmp_dir.scm_gen("foo", "foo", commit="foo")
+
+    (tmp_dir / "foo").write_text("bar")
+
+    with api.open("foo", rev="master") as fobj:
+        assert fobj.read() == "foo"
+
+
 @pytest.mark.parametrize("as_external", [True, False])
 @pytest.mark.parametrize("remote", [pytest.lazy_fixture("ssh")], indirect=True)
 @pytest.mark.parametrize(