diff --git a/conda_forge_tick/update_sources.py b/conda_forge_tick/update_sources.py
index 32d621911..4bad98673 100644
--- a/conda_forge_tick/update_sources.py
+++ b/conda_forge_tick/update_sources.py
@@ -2,11 +2,13 @@
 import collections.abc
 import copy
 import functools
+import json
 import logging
 import re
 import subprocess
 import typing
 import urllib.parse
+from pathlib import Path
 from typing import Iterator, List, Optional
 
 import feedparser
@@ -708,3 +710,46 @@ def get_url(self, meta_yaml) -> Optional[str]:
 
     def get_version(self, url: str) -> Optional[str]:
         return url  # = next version, same as in BaseRawURL
+
+
+class CratesIO(AbstractSource):
+    name = "CratesIO"
+
+    def get_url(self, meta_yaml) -> Optional[str]:
+        if "crates.io" not in meta_yaml["url"]:
+            return None
+
+        pkg = Path(meta_yaml["url"]).parts[5]
+        tier = self._tier_directory(pkg)
+
+        return f"https://index.crates.io/{tier}"
+
+    def get_version(self, url: str) -> Optional[str]:
+        r = requests.get(url)
+
+        if not r.ok:
+            return None
+
+        # the response body is a newline-delimited JSON stream, with the latest version
+        # being the last line
+        latest = json.loads(r.text.splitlines()[-1])
+
+        return latest.get("vers")
+
+    @staticmethod
+    def _tier_directory(package: str) -> str:
+        """Depending on the length of the package name, the tier directory structure
+        will differ.
+        Documented here: https://doc.rust-lang.org/cargo/reference/registry-index.html#index-files
+        """
+        if not package:
+            raise ValueError("Package name cannot be empty")
+
+        name_len = len(package)
+
+        if name_len <= 2:
+            return f"{name_len}/{package}"
+        elif name_len == 3:
+            return f"{name_len}/{package[0]}/{package}"
+        else:
+            return f"{package[0:2]}/{package[2:4]}/{package}"
diff --git a/conda_forge_tick/update_upstream_versions.py b/conda_forge_tick/update_upstream_versions.py
index 931ab4aa7..0e2052622 100644
--- a/conda_forge_tick/update_upstream_versions.py
+++ b/conda_forge_tick/update_upstream_versions.py
@@ -35,6 +35,7 @@
     NPM,
     NVIDIA,
     AbstractSource,
+    CratesIO,
     Github,
     GithubReleases,
     IncrementAlphaRawURL,
@@ -418,6 +419,7 @@ def all_version_sources():
     return (
         PyPI(),
         CRAN(),
+        CratesIO(),
         NPM(),
         ROSDistro(),
         RawURL(),
diff --git a/tests/test_update_sources.py b/tests/test_update_sources.py
new file mode 100644
index 000000000..76bf86a99
--- /dev/null
+++ b/tests/test_update_sources.py
@@ -0,0 +1,91 @@
+from unittest.mock import Mock, patch
+
+import pytest
+
+from conda_forge_tick.update_sources import CratesIO
+
+
+class TestCratesIOTierDirectory:
+    def test_four_or_more_characters(self):
+        pkg = "rasusa"
+
+        actual = CratesIO._tier_directory(pkg)
+        expected = "ra/su/rasusa"
+
+        assert actual == expected
+
+    def test_four_characters(self):
+        pkg = "psdm"
+
+        actual = CratesIO._tier_directory(pkg)
+        expected = "ps/dm/psdm"
+
+        assert actual == expected
+
+    def test_three_characters(self):
+        pkg = "syn"
+
+        actual = CratesIO._tier_directory(pkg)
+        expected = "3/s/syn"
+
+        assert actual == expected
+
+    def test_two_characters(self):
+        pkg = "it"
+
+        actual = CratesIO._tier_directory(pkg)
+        expected = "2/it"
+
+        assert actual == expected
+
+    def test_one_character(self):
+        pkg = "a"
+
+        actual = CratesIO._tier_directory(pkg)
+        expected = "1/a"
+
+        assert actual == expected
+
+    def test_empty_string(self):
+        pkg = ""
+
+        with pytest.raises(ValueError):
+            CratesIO._tier_directory(pkg)
+
+
+class TestCratesIOGetVersion:
+    def test_valid_package(self):
+        # as far as I can tell, this package has not had a new version in the last 9
+        # years, so it should be safe to use for testing as we don't expect the version
+        # to change
+        pkg = "gopher"
+        tier = CratesIO._tier_directory(pkg)
+        url = f"https://index.crates.io/{tier}"
+
+        actual = CratesIO().get_version(url)
+        expected = "0.0.3"
+
+        assert actual == expected
+
+    def test_invalid_package(self):
+        pkg = "shdfbshbvjhbvhsbhsb"
+        tier = CratesIO._tier_directory(pkg)
+        url = f"https://index.crates.io/{tier}"
+
+        result = CratesIO().get_version(url)
+        assert result is None
+
+    @patch("conda_forge_tick.update_sources.requests.get")
+    def test_empty_package(self, mock_get):
+        pkg = "syn"
+        tier = CratesIO._tier_directory(pkg)
+        url = f"https://index.crates.io/{tier}"
+
+        # Mock response
+        mock_response = Mock()
+        mock_response.ok = True
+        mock_response.text = '{"name": "syn"}'
+        mock_get.return_value = mock_response
+
+        result = CratesIO().get_version(url)
+        assert result is None
diff --git a/tests/test_upstream_versions.py b/tests/test_upstream_versions.py
index f15e0ca71..1bc587db6 100644
--- a/tests/test_upstream_versions.py
+++ b/tests/test_upstream_versions.py
@@ -17,6 +17,7 @@
     NPM,
     NVIDIA,
     AbstractSource,
+    CratesIO,
     Github,
     GithubReleases,
     PyPI,
@@ -1254,6 +1255,7 @@ def test_update_upstream_versions_no_packages_to_update(
 default_sources = (
     "PyPI",
     "CRAN",
+    "CratesIO",
     "NPM",
     "ROSDistro",
     "RawURL",
@@ -1718,3 +1720,37 @@ def test_github_releases(tmpdir, url, feedstock_version):
     ghr = GithubReleases()
     url = ghr.get_url(meta_yaml)
     assert VersionOrder(ghr.get_version(url)) > VersionOrder(feedstock_version)
+
+
+def test_latest_version_cratesio(tmpdir):
+    name = "wbg-rand"
+    recipe_path = os.path.join(YAML_PATH, "version_wbg-rand.yaml")
+    curr_ver = "0.4.0"
+    ver = "0.4.1"
+    source = CratesIO()
+
+    with open(recipe_path) as fd:
+        inp = fd.read()
+
+    pmy = LazyJson(os.path.join(str(tmpdir), "cf-scripts-test.json"))
+    with pmy as _pmy:
+        yml = parse_meta_yaml(inp)
+        _pmy.update(yml["source"])
+        _pmy.update(
+            {
+                "feedstock_name": name,
+                "version": curr_ver,
+                "raw_meta_yaml": inp,
+                "meta_yaml": yml,
+            },
+        )
+
+    attempt = get_latest_version(name, pmy, [source], use_container=False)
+    if ver is None:
+        assert attempt["new_version"] is not False
+        assert attempt["new_version"] != curr_ver
+        assert VersionOrder(attempt["new_version"]) > VersionOrder(curr_ver)
+    elif ver is False:
+        assert attempt["new_version"] is ver
+    else:
+        assert ver == attempt["new_version"]
diff --git a/tests/test_yaml/version_wbg-rand.yaml b/tests/test_yaml/version_wbg-rand.yaml
new file mode 100644
index 000000000..9814429be
--- /dev/null
+++ b/tests/test_yaml/version_wbg-rand.yaml
@@ -0,0 +1,37 @@
+package:
+  name: wbg-rand
+  version: "0.4.0"
+
+source:
+  url: https://crates.io/api/v1/crates/wbg-rand/0.4.0/download
+  fn: "wbg-rand-0.4.0.tar.gz"
+  sha256: 5505e10cb191f56fed835c35baf4ac97b5466148a13fbcaeb1173198b1a52b4c
+
+build:
+  number: 0
+  skip: true  # [win]
+
+requirements:
+  build:
+    - {{ compiler('rust') }}
+    - {{ compiler('c') }}
+    - {{ stdlib("c") }}
+    - cargo-bundle-licenses
+
+test:
+  commands:
+    - echo "This is a placeholder for the test section"
+
+about:
+  home: https://github.com/alexcrichton/wbg-rand
+  summary: 'Random numbers for wasm32-unknown-unknown in Rust'
+  description: |
+    Implementation of rand for wasm32-unknown-unknown in Rust using #[wasm_bindgen].
+  license: MIT AND Apache-2.0
+  license_file:
+    - LICENSE-MIT
+    - LICENSE-APACHE
+
+extra:
+  recipe-maintainers:
+    - mbhall88