diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index 627d951..7184dfc 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -19,8 +19,12 @@ git clone git@github.com:bufbuild/protovalidate-python.git
 cd protovalidate-python
 ```
 
-Then, make any changes you'd like. We use a Makefile to test and lint our code,
-so you'll need a few non-Python tools:
+Next, install dependencies. You will need:
+
+* Python >=v3.9
+* [Pipenv](https://pipenv.pypa.io/en/latest/index.html)
+
+We use a Makefile to test and lint our code, so you'll also need a few non-Python tools:
 
 * GNU Make (to use the Makefile): part of the `build-essential` package on
   Debian-derived Linux distributions (including Ubuntu), and part of
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index e1c012d..8dd4a7c 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -32,6 +32,8 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
+          cache: "pipenv"
+      - run: ${{steps.python.outputs.python-path}}  -m pip install --upgrade pip pipenv
       - name: Execute tests
         run: make test PYTHON=${{ steps.python.outputs.python-path }}
       - name: Lint
diff --git a/.github/workflows/conformance.yaml b/.github/workflows/conformance.yaml
index e6f2178..6102076 100644
--- a/.github/workflows/conformance.yaml
+++ b/.github/workflows/conformance.yaml
@@ -32,5 +32,7 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
+          cache: "pipenv"
+      - run: ${{steps.python.outputs.python-path}}  -m pip install --upgrade pip pipenv
       - name: Test conformance
         run: make conformance PYTHON=${{ steps.python.outputs.python-path }}
diff --git a/Makefile b/Makefile
index a96320b..f5bc54e 100644
--- a/Makefile
+++ b/Makefile
@@ -62,7 +62,6 @@ lint: install ## Lint code
 
 .PHONY: install
 install: ## Install dependencies
-	$(PYTHON) -m pip install --upgrade pip pipenv
 	pipenv --python $(PYTHON) sync --dev
 
 .PHONY: checkgenerate
diff --git a/Pipfile b/Pipfile
index 0163de0..e8d4884 100644
--- a/Pipfile
+++ b/Pipfile
@@ -11,7 +11,7 @@ protobuf = "==6.*"
 pytest = "*"
 mypy = "*"
 ruff = "*"
-types-protobuf = "*"
+types-protobuf = "==6.30.2.20250503"
 exceptiongroup = "*"
 tomli = "*"
 
diff --git a/Pipfile.lock b/Pipfile.lock
index a92ddd1..1f812aa 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "2244230d5507f6a004047e0856c65eea89ab850a6932e9a2e96f63511b32a3ff"
+            "sha256": "f546975999f17cdad6eecce592ae22a1710abe4959bc3757e67e3fdd581548ae"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -141,11 +141,11 @@
         },
         "types-pyyaml": {
             "hashes": [
-                "sha256:7f07622dbd34bb9c8b264fe860a17e0efcad00d50b5f27e93984909d9363498c",
-                "sha256:fa4d32565219b68e6dee5f67534c722e53c00d1cfc09c435ef04d7353e1e96e6"
+                "sha256:652348fa9e7a203d4b0d21066dfb00760d3cbd5a15ebb7cf8d33c88a49546681",
+                "sha256:d7c13c3e6d335b6af4b0122a01ff1d270aba84ab96d1a1a1063ecba3e13ec075"
             ],
-            "markers": "python_version >= '3.8'",
-            "version": "==6.0.12.20241230"
+            "markers": "python_version >= '3.9'",
+            "version": "==6.0.12.20250402"
         }
     },
     "develop": {
@@ -160,11 +160,11 @@
         },
         "iniconfig": {
             "hashes": [
-                "sha256:2d91e135bf72d31a410b17c16da610a82cb55f6b0477d1a902134b24a455b8b3",
-                "sha256:b6a85871a79d2e3b22d2d1b94ac2824226a63c6b741c88f7ae975f18b6778374"
+                "sha256:3abbd2e30b36733fee78f9c7f7308f2d0050e88f0087fd25c2645f63c773e1c7",
+                "sha256:9deba5723312380e77435581c6bf4935c94cbfab9b1ed33ef8d238ea168eb760"
             ],
-            "markers": "python_version >= '3.7'",
-            "version": "==2.0.0"
+            "markers": "python_version >= '3.8'",
+            "version": "==2.1.0"
         },
         "mypy": {
             "hashes": [
@@ -207,19 +207,19 @@
         },
         "mypy-extensions": {
             "hashes": [
-                "sha256:4392f6c0eb8a5668a69e23d168ffa70f0be9ccfd32b5cc2d26a34ae5b844552d",
-                "sha256:75dbf8955dc00442a438fc4d0666508a9a97b6bd41aa2f0ffe9d2f2725af0782"
+                "sha256:1be4cccdb0f2482337c4743e60421de3a356cd97508abadd57d47403e94f5505",
+                "sha256:52e68efc3284861e772bbcd66823fde5ae21fd2fdb51c62a211403730b916558"
             ],
-            "markers": "python_version >= '3.5'",
-            "version": "==1.0.0"
+            "markers": "python_version >= '3.8'",
+            "version": "==1.1.0"
         },
         "packaging": {
             "hashes": [
-                "sha256:09abb1bccd265c01f4a3aa3f7a7db064b36514d2cba19a2f694fe6150451a759",
-                "sha256:c228a6dc5e932d346bc5739379109d49e8853dd8223571c7c5b55260edc0b97f"
+                "sha256:29572ef2b1f17581046b3a2227d5c611fb25ec70ca1ba8554b24b0e69331a484",
+                "sha256:d443872c98d677bf60f6a1f2f8c1cb748e8fe762d2bf9d3148b5599295b0fc4f"
             ],
             "markers": "python_version >= '3.8'",
-            "version": "==24.2"
+            "version": "==25.0"
         },
         "pluggy": {
             "hashes": [
@@ -313,11 +313,11 @@
         },
         "typing-extensions": {
             "hashes": [
-                "sha256:04e5ca0351e0f3f85c6853954072df659d0d13fac324d0072316b67d7794700d",
-                "sha256:1a7ead55c7e559dd4dee8856e3a88b41225abfe1ce8df57b7c13915fe121ffb8"
+                "sha256:a439e7c04b49fec3e5d3e2beaa21755cadbbdc391694e28ccdd36ca4a1408f8c",
+                "sha256:e6c81219bd689f51865d9e372991c540bda33a0379d5573cddb9a3a23f7caaef"
             ],
             "markers": "python_version >= '3.8'",
-            "version": "==4.12.2"
+            "version": "==4.13.2"
         }
     }
 }
diff --git a/pyproject.toml b/pyproject.toml
index ac8554a..883d40e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,8 @@ build-backend = "hatchling.build"
 name = "protovalidate"
 description = "Protocol Buffer Validation for Python"
 readme = "README.md"
-license = { file = "LICENSE" }
+license-expression = "Apache 2.0"
+license-file = "LICENSE"
 keywords = ["validate", "protobuf", "protocol buffer"]
 requires-python = ">=3.9"
 classifiers = [
@@ -15,7 +16,6 @@ classifiers = [
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
-  "License :: OSI Approved :: Apache Software License",
   "Operating System :: OS Independent",
   "Typing :: Typed",
 ]