diff --git a/.github/workflows/ci_test.yml b/.github/workflows/ci_test.yml
index 79d3ca0a2..e550e50d4 100644
--- a/.github/workflows/ci_test.yml
+++ b/.github/workflows/ci_test.yml
@@ -41,9 +41,9 @@ jobs:
 #          - os: ubuntu-latest
 #            python: '3.10'
 #            tox_env: 'py310-test-alldeps-cov'
-          - os: macos-12
-            python: '3.13'
-            tox_env: 'py313-test'
+          # - os: macos-12
+          #   python: '3.13'
+          #   tox_env: 'py313-test'
 #          - os: windows-latest
 #            python: '3.8'
 #            tox_env: 'py38-test'
@@ -94,3 +94,47 @@ jobs:
 #      with:
 #          name: documentation
 #          path: .tox/docs_out/
+  macos-latest-py313:
+    runs-on: macos-latest
+    steps:
+        - uses: actions/checkout@v4
+        - name: Set-Up Python Env
+          uses: mamba-org/setup-micromamba@v1
+          with: 
+            init-shell: bash
+            environment-name: pint
+            cache-environment: true
+            cache-downloads: true
+            create-args: >-
+              --platform osx-64
+              -c conda-forge
+              python=3.13
+              astropy
+              git
+        - name: Install base dependencies
+          shell: bash -el {0}
+          run: |
+            python -m pip install --upgrade pip
+            python -m pip install tox pytest hypothesis numdifftools pathos setuptools
+        - name: Print OS, machine info
+          shell: bash -el {0}
+          run: |
+            python -c "import os; print(f'os {os.uname()}')"
+            python -c "import platform; print(f'processor {platform.processor()}')"
+            python -c "import numpy as np; print(f'eps: {np.finfo(np.longdouble).eps}')"
+        - name: Print Python, pip, and tox versions
+          shell: bash -el {0}
+          run: |
+            python -c "import sys; print(f'Python {sys.version}')"
+            python -c "import pip; print(f'pip {pip.__version__}')"
+            python -c "import tox; print(f'tox {tox.__version__}')"
+        - name: Install PINT and requirements
+          shell: bash -el {0}
+          run: |
+            python -m pip install -r requirements.txt
+            python -m pip install -r requirements_dev.txt
+            python -m pip install --force-reinstall --no-deps .
+        - name: Run tests
+          shell: bash -el {0}
+          run: pytest -v --pyargs tests
+          
\ No newline at end of file
diff --git a/CHANGELOG-unreleased.md b/CHANGELOG-unreleased.md
index cd766f352..120c8a73e 100644
--- a/CHANGELOG-unreleased.md
+++ b/CHANGELOG-unreleased.md
@@ -20,8 +20,11 @@ the released changes.
 - When TCB->TDB conversion info is missing, will print parameter name
 - Piecewise-constant model for chromatic variations (CMX)
 - `add_param` returns the name of the parameter (useful for numbered parameters)
+- micromamba CI environment for testing macOS-latest, without tox
 ### Fixed
 - Changed WAVE_OM units from 1/d to rad/d.
 - When EQUAD is created from TNEQ, has proper TCB->TDB conversion info
 - TOA selection masks will work when only TOA is the first one
 ### Removed
+- macOS 12 CI 
+
diff --git a/requirements_dev.txt b/requirements_dev.txt
index f5dfff94b..de85bbaca 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -27,7 +27,6 @@ jupytext
 pdbpp
 tox
 pre-commit
-typed-ast>=1.5.0
 black~=24.0
 pygments
 ipython
diff --git a/tests/test_phase_offset.py b/tests/test_phase_offset.py
index d28fc26c0..61d46bd5f 100644
--- a/tests/test_phase_offset.py
+++ b/tests/test_phase_offset.py
@@ -26,7 +26,7 @@ def test_phase_offset():
     m = get_model(io.StringIO(simplepar))
 
     assert hasattr(m, "PHOFF") and m.PHOFF.value == 0.2
-
+    np.random.seed(1929)
     t = make_fake_toas_uniform(
         startMJD=50000,
         endMJD=50500,
diff --git a/tox.ini b/tox.ini
index efadd9b9c..60f8fa754 100644
--- a/tox.ini
+++ b/tox.ini
@@ -66,7 +66,7 @@ deps =
     hypothesis<=6.72.0
     setuptools
 # can change this as needed for a single test run
-commands = pytest tests/test_model_derivatives.py
+commands = pytest tests/test_precision.py
 
 
 [testenv:ephemeris_connection]