diff --git a/conda_index/index/__init__.py b/conda_index/index/__init__.py
index 67e841c..648e1dd 100644
--- a/conda_index/index/__init__.py
+++ b/conda_index/index/__init__.py
@@ -46,7 +46,12 @@
 
     V3Section = TypedDict(
         "V3Section",
-        {"tar.bz2": dict, "conda": dict, "whl": dict},
+        {
+            "tar.bz2": dict[str, dict[str, Any]],
+            "conda": dict[str, dict[str, Any]],
+            "whl": dict[str, dict[str, Any]],
+        },
+        closed=True,
     )
 
     # in this style because "packages.conda" is not a Python identifier
@@ -206,7 +211,7 @@ def _make_seconds(timestamp):
 )
 CHANNELDATA_VERSION = 1
 RUN_EXPORTS_VERSION = 1
-REPODATA_REVISION_V3 = 3
+REPODATA_REVISION_V3 = "v3"
 REPODATA_JSON_FN = "repodata.json"
 REPODATA_FROM_PKGS_JSON_FN = "repodata_from_packages.json"
 REPODATA_SHARDS_FN = "repodata_shards.msgpack.zst"
@@ -746,7 +751,7 @@ def index_subdir_shards(self, subdir, verbose=False, progress=False):
 
             (self.output_root / subdir).mkdir(parents=True, exist_ok=True)
 
-            v3_data = {
+            v3_data: V3Section = {
                 "tar.bz2": {},
                 "conda": {},
                 "whl": {},
@@ -766,13 +771,13 @@ def index_subdir_shards(self, subdir, verbose=False, progress=False):
                 shards[shard.name] = shard_hash
 
                 if self.repodata_v3:
-                    for section, records in repodata_shard["v3"].items():
+                    for section, records in repodata_shard.get("v3", {}).items():
                         v3_data[section].update(records)
 
             if self.repodata_v3:
-                shards_index["info"]["repodata_revisions"] = [
-                    self._make_repodata_revision_data(v3_data)
-                ]
+                revision_data = self._make_repodata_revision_data(v3_data)
+                revision = revision_data.pop("revision")
+                shards_index["info"]["repodata_revisions"] = {revision: revision_data}
 
             return shards_index
 
@@ -803,9 +808,9 @@ def index_subdir(self, subdir, verbose=False, progress=False):
             new_repodata["v3"] = v3_packages
             new_repodata["packages"] = {}
             new_repodata["packages.conda"] = {}
-            new_repodata["info"]["repodata_revisions"] = [
-                self._make_repodata_revision_data(v3_packages)
-            ]
+            revision_data = self._make_repodata_revision_data(v3_packages)
+            revision = revision_data.pop("revision")
+            new_repodata["info"]["repodata_revisions"] = {revision: revision_data}
 
         if self.base_url:
             # per https://github.com/conda-incubator/ceps/blob/main/cep-15.md
@@ -878,8 +883,8 @@ def _indexed_shard_to_repodata(self, indexed_shard: IndexedShard) -> ShardDict:
 
     @staticmethod
     def _make_repodata_revision_data(
-        revision_data: dict[str, dict[str, dict]],
-    ) -> dict[str, int | None]:
+        revision_data: V3Section,
+    ) -> dict[str, int | str | None]:
         """
         Return { "revision": 3, ... } dict with package statistics derived from
         revision_data, which is similar to monolithic repodata.
diff --git a/docs/v3-repodata.md b/docs/v3-repodata.md
index 9504093..5a7849e 100644
--- a/docs/v3-repodata.md
+++ b/docs/v3-repodata.md
@@ -28,14 +28,13 @@ structure:
 ```json
 {
   "info": {
-    "repodata_revisions": [
-      {
+    "repodata_revisions": {
+      "v3": {
         "n_packages": 1,
         "newest": 1758039171969,
-        "oldest": 1758039171969,
-        "revision": 3
+        "oldest": 1758039171969
       }
-    ],
+    },
     "subdir": "noarch"
   },
   "packages": {},
diff --git a/news/338-repodata-revisions-map b/news/338-repodata-revisions-map
new file mode 100644
index 0000000..695ef07
--- /dev/null
+++ b/news/338-repodata-revisions-map
@@ -0,0 +1,4 @@
+### Bug fixes
+
+* Change `info.repodata_revisions` from a list to a map keyed by revision id to
+  be compatible with py-rattler 0.25.0+. (#338)
diff --git a/tests/test_index.py b/tests/test_index.py
index 9a03017..b7e451c 100644
--- a/tests/test_index.py
+++ b/tests/test_index.py
@@ -1378,9 +1378,8 @@ def test_repodata_v3(index_data):
 
     noarch = json.loads((pkg_dir / "noarch" / "repodata.json").read_text())
 
-    assert set(noarch["info"]["repodata_revisions"][0].keys()) == set(
-        ("revision", "n_packages", "oldest", "newest")
-    )
+    revision_data = list(noarch["info"]["repodata_revisions"].values())[0]
+    assert set(revision_data.keys()) == set(("n_packages", "oldest", "newest"))
 
     assert "v3" in noarch
     assert set(noarch["v3"]) == {"tar.bz2", "conda", "whl"}
@@ -1529,14 +1528,13 @@ def test_index_v3_format(tmp_path):
             "shards_base_url": "",
             "subdir": "noarch",
             "created_at": CREATED_AT,
-            "repodata_revisions": [
-                {
-                    "revision": 3,
+            "repodata_revisions": {
+                "v3": {
                     "n_packages": 0,
                     "oldest": None,
                     "newest": None,
                 }
-            ],
+            },
         },
         "shards": {},
     }
@@ -1547,14 +1545,13 @@ def test_index_v3_format(tmp_path):
         "packages.conda": {},
         "info": {
             "subdir": "noarch",
-            "repodata_revisions": [
-                {
-                    "revision": 3,
+            "repodata_revisions": {
+                "v3": {
                     "n_packages": 0,
                     "oldest": None,
                     "newest": None,
                 }
-            ],
+            },
         },
         "repodata_version": 1,
         "removed": [],