diff --git a/fastapi/middleware/security_headers.py b/fastapi/middleware/security_headers.py
index 6ae127ad7..f08d48091 100644
--- a/fastapi/middleware/security_headers.py
+++ b/fastapi/middleware/security_headers.py
@@ -40,8 +40,8 @@ class SecurityHeadersMiddleware:
                 cross_origin_opener_policy.encode("latin-1")
             )
         if content_security_policy is not None:
-            self._headers[b"content-security-policy"] = (
-                content_security_policy.encode("latin-1")
+            self._headers[b"content-security-policy"] = content_security_policy.encode(
+                "latin-1"
             )
         if permissions_policy is not None:
             self._headers[b"permissions-policy"] = permissions_policy.encode("latin-1")
diff --git a/tests/test_security_headers_middleware.py b/tests/test_security_headers_middleware.py
index 8da5766c9..d889aed96 100644
--- a/tests/test_security_headers_middleware.py
+++ b/tests/test_security_headers_middleware.py
@@ -191,9 +191,7 @@ def test_cache_control():
         return {"message": "hi"}
 
     response = client2.get("/")
-    assert (
-        response.headers["cache-control"] == "no-store, no-cache, must-revalidate"
-    )
+    assert response.headers["cache-control"] == "no-store, no-cache, must-revalidate"
 
 
 def test_custom_x_frame_options():
@@ -235,9 +233,7 @@ def test_custom_cross_origin_opener_policy():
         return {"message": "hi"}
 
     response = client2.get("/")
-    assert (
-        response.headers["cross-origin-opener-policy"] == "same-origin-allow-popups"
-    )
+    assert response.headers["cross-origin-opener-policy"] == "same-origin-allow-popups"
 
 
 def test_websocket_not_affected():