diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 50f14bbb..07e45357 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -73,6 +73,11 @@ jobs:
       run: |
         nvidia-smi || (echo "❌ No GPU detected" && exit 1)
         python -c "import torch; assert torch.cuda.is_available(), '❌ GPU not found'; print('✅ Found GPU:', torch.cuda.get_device_name(0))"
+    - name: Cache model checkpoints
+      uses: actions/cache@v4
+      with:
+        path: ~/.cache/torch/syntheseus
+        key: model-checkpoints-${{ hashFiles('syntheseus/reaction_prediction/inference/default_checkpoint_ids.yml') }}
     - name: Run single-step model tests
       run: |
         coverage run -p -m pytest \
diff --git a/pyproject.toml b/pyproject.toml
index 8c07c86b..687806f5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,6 +33,7 @@ viz = [
 dev = [
   "pytest",
   "pytest-cov",
+  "pytest-forked",
   "pytest-rerunfailures",
   "pre-commit"
 ]
diff --git a/syntheseus/tests/cli/test_cli.py b/syntheseus/tests/cli/test_cli.py
index ca65bad4..6c346e8b 100644
--- a/syntheseus/tests/cli/test_cli.py
+++ b/syntheseus/tests/cli/test_cli.py
@@ -1,6 +1,7 @@
 import glob
 import json
 import math
+import subprocess
 import sys
 import tempfile
 import urllib
@@ -8,7 +9,6 @@
 from pathlib import Path
 from typing import Generator, List
 
-import omegaconf
 import pytest
 
 from syntheseus.reaction_prediction.inference.config import BackwardModelClass
@@ -21,7 +21,7 @@
 )
 
 
-MODEL_CLASSES_TO_TEST = set(BackwardModelClass) - {BackwardModelClass.GLN}
+MODEL_CLASSES_TO_TEST = [m for m in BackwardModelClass if m is not BackwardModelClass.GLN]
 
 
 @pytest.fixture(scope="module")
@@ -66,12 +66,13 @@ def search_cli_argv() -> List[str]:
 
 
 def run_cli_with_argv(argv: List[str]) -> None:
-    # The import below pulls in some optional dependencies, so do it locally to avoid executing it
-    # if the test suite is being skipped.
-    from syntheseus.cli.main import main
+    # Run in a subprocess so that model memory is fully reclaimed after each test.
+    result = subprocess.run(
+        [sys.executable, "-m", "syntheseus.cli.main"] + argv, capture_output=True, text=True
+    )
 
-    sys.argv = ["syntheseus"] + argv
-    main()
+    if result.returncode != 0:
+        raise RuntimeError("CLI failed")
 
 
 def test_cli_invalid(
@@ -103,7 +104,7 @@ def test_cli_invalid(
     ]
 
     for argv in argv_lists:
-        with pytest.raises((ValueError, omegaconf.errors.MissingMandatoryValue)):
+        with pytest.raises(RuntimeError):
             run_cli_with_argv(argv)
 
 
diff --git a/syntheseus/tests/conftest.py b/syntheseus/tests/conftest.py
index 538e74a9..ab556837 100644
--- a/syntheseus/tests/conftest.py
+++ b/syntheseus/tests/conftest.py
@@ -1,11 +1,17 @@
 from __future__ import annotations
 
+import os
+
 import pytest
 
 from syntheseus.interface.bag import Bag
 from syntheseus.interface.molecule import Molecule
 from syntheseus.interface.reaction import SingleProductReaction
 
+# Make `torch.cuda.is_available()` fork-safe so that calling it in the parent process does not
+# poison `@pytest.mark.forked` tests (otherwise could run into CUDA reinitialization issues).
+os.environ.setdefault("PYTORCH_NVML_BASED_CUDA_CHECK", "1")
+
 
 @pytest.fixture
 def cocs_mol() -> Molecule:
diff --git a/syntheseus/tests/reaction_prediction/inference/test_models.py b/syntheseus/tests/reaction_prediction/inference/test_models.py
index 99d31128..41a4de1a 100644
--- a/syntheseus/tests/reaction_prediction/inference/test_models.py
+++ b/syntheseus/tests/reaction_prediction/inference/test_models.py
@@ -12,15 +12,16 @@
 )
 
 
-MODEL_CLASSES_TO_TEST = set(BackwardModelClass) - {BackwardModelClass.GLN}
+MODEL_CLASSES_TO_TEST = [m for m in BackwardModelClass if m is not BackwardModelClass.GLN]
 
 
-@pytest.fixture(scope="module", params=list(MODEL_CLASSES_TO_TEST) * 2)
+@pytest.fixture(params=MODEL_CLASSES_TO_TEST)
 def model(request) -> ExternalBackwardReactionModel:
     model_cls = request.param.value
     return model_cls()
 
 
+@pytest.mark.forked
 def test_call(model: ExternalBackwardReactionModel) -> None:
     [result] = model([Molecule("Cc1ccc(-c2ccc(C)cc2)cc1")], num_results=20)
     model_predictions = [prediction.reactants for prediction in result]
@@ -35,10 +36,10 @@ def test_call(model: ExternalBackwardReactionModel) -> None:
     # The model should recover at least two (out of six) in its top-20.
     assert len(set(expected_predictions) & set(model_predictions)) >= 2
 
-
-def test_misc(model: ExternalBackwardReactionModel) -> None:
     import torch
 
+    # Additionally test some misc properties and methods.
+
     assert isinstance(model.name, str)
     assert isinstance(model.get_model_info(), dict)
     assert model.is_backward() is not model.is_forward()