diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 9143015e..c1020dd8 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -22,7 +22,7 @@ jobs:
                       # numba doesn't yet support numpy/2.3; could be relaxed in the future
                       numpy-version: '<2.3'
                       scipy-version: ''
-                      astropy-version: '<7'
+                      astropy-version: '<8'
                     - os: ubuntu-latest
                       python-version: '3.12'
                       numpy-version: '<2.3'
@@ -40,7 +40,7 @@ jobs:
                       scipy-version: '<1.9'
                       astropy-version: '<6.1'
         env:
-            DESIUTIL_VERSION: 3.5.2
+            DESIUTIL_VERSION: 3.6.0
             # DESIMODEL: ${GITHUB_WORKSPACE}/desimodel
             # desisim -> specsim needs data/specpsf/psf-quicksim-rebin.fits which isn't in trimmed down test data
             DESIMODEL_DATA: trunk
@@ -66,12 +66,12 @@ jobs:
               run: |
                 python -m pip install --upgrade pip 'setuptools<80' wheel
                 python -m pip install pytest
-                python -m pip install git+https://github.com/desihub/desiutil.git@${DESIUTIL_VERSION}#egg=desiutil
-                python -m pip install -r requirements.txt
+                python -m pip install desiutil==${DESIUTIL_VERSION}
+                python -m pip install --no-build-isolation -r requirements.txt
                 python -m pip install --upgrade --upgrade-strategy only-if-needed 'numpy${{ matrix.numpy-version }}'
                 python -m pip install --upgrade --upgrade-strategy only-if-needed 'scipy${{ matrix.scipy-version }}'
                 python -m pip install --upgrade --upgrade-strategy only-if-needed 'astropy${{ matrix.astropy-version }}'
-                python -m pip install git+https://github.com/${SIMQSO_REPO}/simqso.git@${SIMQSO_VERSION}#egg=simqso
+                python -m pip install --no-build-isolation git+https://github.com/${SIMQSO_REPO}/simqso.git@${SIMQSO_VERSION}#egg=simqso
             - name: Verify Installation
               run: pip list
             - name: Install desimodel Data
@@ -104,7 +104,7 @@ jobs:
                 numpy-version: ['<2']
                 scipy-version: ['<1.9']
         env:
-            DESIUTIL_VERSION: 3.5.2
+            DESIUTIL_VERSION: 3.6.0
             # DESIMODEL: ${GITHUB_WORKSPACE}/desimodel
             # desisim -> specsim needs data/specpsf/psf-quicksim-rebin.fits which isn't in trimmed down test data
             DESIMODEL_DATA: trunk
@@ -128,12 +128,12 @@ jobs:
               run: |
                 python -m pip install --upgrade pip 'setuptools<80' wheel
                 python -m pip install pytest pytest-cov coveralls
-                python -m pip install git+https://github.com/desihub/desiutil.git@${DESIUTIL_VERSION}#egg=desiutil
-                python -m pip install -r requirements.txt
+                python -m pip install desiutil==${DESIUTIL_VERSION}
+                python -m pip install --no-build-isolation -r requirements.txt
                 python -m pip install --upgrade --upgrade-strategy only-if-needed 'numpy${{ matrix.numpy-version }}'
                 python -m pip install --upgrade --upgrade-strategy only-if-needed 'scipy${{ matrix.scipy-version }}'
                 python -m pip install --upgrade --upgrade-strategy only-if-needed 'astropy${{ matrix.astropy-version }}'
-                python -m pip install git+https://github.com/${SIMQSO_REPO}/simqso.git@${SIMQSO_VERSION}#egg=simqso
+                python -m pip install --no-build-isolation git+https://github.com/${SIMQSO_REPO}/simqso.git@${SIMQSO_VERSION}#egg=simqso
                 python -m pip cache remove fitsio
                 python -m pip install --no-deps --force-reinstall --ignore-installed 'fitsio${{ matrix.fitsio-version }}'
             - name: Verify Installation