diff --git a/docs/api-reference/json.rst b/docs/api-reference/json.rst
index cd216591551d..8fa3982cff66 100644
--- a/docs/api-reference/json.rst
+++ b/docs/api-reference/json.rst
@@ -167,6 +167,7 @@ Project
                     "yanked_reason": null
                 }
             ],
+            "versions": ["1.0", "1.2.0"],
             "vulnerabilities": []
         }
 
diff --git a/tests/unit/legacy/api/test_json.py b/tests/unit/legacy/api/test_json.py
index b3dd1d7c4530..e3254806fa06 100644
--- a/tests/unit/legacy/api/test_json.py
+++ b/tests/unit/legacy/api/test_json.py
@@ -326,6 +326,7 @@ def test_renders(self, pyramid_config, db_request, db_session):
                     }
                 ],
             },
+            "versions": ["0.1", "1.0", "2.0", "3.0"],
             "urls": [
                 {
                     "comment_text": None,
diff --git a/warehouse/legacy/api/json.py b/warehouse/legacy/api/json.py
index 1cbe3bef43f6..1ee70c60c1ac 100644
--- a/warehouse/legacy/api/json.py
+++ b/warehouse/legacy/api/json.py
@@ -173,6 +173,7 @@ def _json_data(request, project, release, *, all_releases):
 
     if all_releases:
         data["releases"] = releases
+        data["versions"] = sorted(releases)
 
     return data