diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..7c6c35d
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,19 @@
+# Reference:
+#   - https://docs.github.com/en/code-security/supply-chain-security/keeping-your-dependencies-updated-automatically/keeping-your-actions-up-to-date-with-dependabot
+
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    target-branch: "dependencies"
+    labels: ["dependencies"]
+
+  - package-ecosystem: "pip"
+    directory: "/requirements"
+    schedule:
+      interval: "daily"
+    target-branch: "dependencies"
+    labels: ["dependencies"]
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 361ec15..754077d 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -16,6 +16,6 @@ sphinx:
 
 python:
   install:
-    - requirements: requirements-docs.txt
+    - requirements: requirements-docs.in
     - method: pip
       path: .
diff --git a/noxfile.py b/noxfile.py
index 4b01190..49c930a 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -14,12 +14,14 @@
 @nox.session
 def test(session: nox.Session) -> None:
     """Run the tests."""
-    session.install(".[units,testing]")
+    session.install("-r", "requirements/required.txt", ".[units,testing]")
 
     args = ["--cov", PROJECT, "-vvv"] + session.posargs
 
     if "CI" in os.environ:
         args.append(f"--cov-report=xml:{ROOT.absolute()!s}/coverage.xml")
+
+    session.run("pip", "list")
     session.run("pytest", *args)
 
     if "CI" not in os.environ:
@@ -29,9 +31,10 @@ def test(session: nox.Session) -> None:
 @nox.session(name="test-cli", python=PYTHON_VERSION, venv_backend="conda")
 def test_cli(session: nox.Session) -> None:
     """Run the tests."""
-    session.install(".[units]")
+    session.install("-r", "requirements/required.txt", ".[units,testing]")
     session.conda_install("pymt_topography", channel=["nodefaults", "conda-forge"])
 
+    session.run("pip", "list")
     session.run("bmi-test", "pymt_topography:Topography")
 
 
@@ -57,11 +60,7 @@ def build_docs(session: nox.Session) -> None:
 
     build_generated_docs(session)
 
-    session.install(
-        *("-r", "requirements-docs.txt"),
-        *("-r", "requirements.txt"),
-    )
-    session.install(".")
+    session.install("-r", "requirements-docs.in", ".[units]")
 
     pathlib.Path("build").mkdir(exist_ok=True)
 
@@ -83,7 +82,7 @@ def build_generated_docs(session: nox.Session) -> None:
     # FOLDER["docs_generated"].mkdir(exist_ok=True)
 
     session.install("sphinx")
-    session.install("-e", ".")
+    session.install("-e", ".[units]")
 
     with session.chdir(ROOT):
         os.makedirs("src/docs/_generated/api", exist_ok=True)
diff --git a/pyproject.toml b/pyproject.toml
index 30feaa6..a3b31d2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,7 +48,7 @@ text = "MIT"
 
 [project.optional-dependencies]
 units = [
-	"gimli.units>=0.3.2"
+    "gimli.units>=0.3.2",
 ]
 dev = [
     "black",
@@ -61,6 +61,9 @@ testing = [
     "pytest>=3.6",
 ]
 docs = [
+    "myst-parser",
+    "sphinx-copybutton",
+    "sphinx-inline-tabs",
     "sphinx>=1.5.1",
 ]
 build = [
diff --git a/requirements-docs.txt b/requirements-docs.in
similarity index 100%
rename from requirements-docs.txt
rename to requirements-docs.in
diff --git a/requirements-testing.txt b/requirements-testing.in
similarity index 100%
rename from requirements-testing.txt
rename to requirements-testing.in
diff --git a/requirements.in b/requirements.in
new file mode 100644
index 0000000..b10d0eb
--- /dev/null
+++ b/requirements.in
@@ -0,0 +1,7 @@
+gimli.units>=0.3.2
+importlib-resources; python_version < '3.12'
+model-metadata>=0.8.1
+numpy
+pytest
+pytest-dependency
+standard-names>=0.2.8
diff --git a/requirements.txt b/requirements.txt
deleted file mode 100644
index 881f1d5..0000000
--- a/requirements.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-model_metadata
-numpy
-pytest
-pytest-dependency
-standard_names
diff --git a/requirements/required.txt b/requirements/required.txt
new file mode 100644
index 0000000..3f422b2
--- /dev/null
+++ b/requirements/required.txt
@@ -0,0 +1,3 @@
+gimli.units==0.3.2
+model-metadata==0.8.1
+standard-names==0.2.8