diff --git a/news/8293.feature b/news/8293.feature
new file mode 100644
index 00000000000..482a58b0e67
--- /dev/null
+++ b/news/8293.feature
@@ -0,0 +1 @@
+Support ``--unstable-feature`` in requirements files
diff --git a/src/pip/_internal/req/req_file.py b/src/pip/_internal/req/req_file.py
index 63cab76f6f2..0a540bdcfa4 100644
--- a/src/pip/_internal/req/req_file.py
+++ b/src/pip/_internal/req/req_file.py
@@ -63,6 +63,7 @@
     cmdoptions.require_hashes,
     cmdoptions.pre,
     cmdoptions.trusted_host,
+    cmdoptions.unstable_feature,
     cmdoptions.always_unzip,  # Deprecated
 ]  # type: List[Callable[..., optparse.Option]]
 
diff --git a/tests/unit/test_req_file.py b/tests/unit/test_req_file.py
index 4ef4f7217e0..a49b8091ef3 100644
--- a/tests/unit/test_req_file.py
+++ b/tests/unit/test_req_file.py
@@ -382,6 +382,10 @@ def test_noop_always_unzip(self, line_processor, finder):
         # noop, but confirm it can be set
         line_processor("--always-unzip", "file", 1, finder=finder)
 
+    def test_unstable_feature(self, line_processor):
+        """--unstable-feature can be set in requirements files."""
+        line_processor("--unstable-feature=resolver", "filename", 1)
+
     def test_set_finder_allow_all_prereleases(self, line_processor, finder):
         line_processor("--pre", "file", 1, finder=finder)
         assert finder.allow_all_prereleases