diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 81200d5..03de9d6 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -39,6 +39,8 @@ jobs:
         python-version:
           - "3.10"
           - "3.11"
+          - "3.12"
+          - "3.13"
     runs-on: ${{ matrix.os }}-latest
 
     # this is needed for conda environments to activate automatically
@@ -48,12 +50,12 @@ jobs:
 
     steps:
     - name: Get source code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         fetch-depth: 0
 
     - name: Cache conda packages
-      uses: actions/cache@v4
+      uses: actions/cache@v5
       env:
         # increment to reset cache
         CACHE_NUMBER: 0
@@ -66,9 +68,8 @@ jobs:
       uses: conda-incubator/setup-miniconda@v3
       with:
         activate-environment: test
-        miniforge-variant: Mambaforge
+        miniforge-variant: Miniforge3
         python-version: ${{ matrix.python-version }}
-        use-mamba: true
 
     - name: Conda info
       run: conda info --all
@@ -76,15 +77,15 @@ jobs:
     - name: Install dependencies
       run: |
         # parse requirements to install as much as possible with conda
-        mamba create --name pip2conda pip2conda
-        mamba run --name pip2conda pip2conda \
+        conda create --name pip2conda --quiet --yes pip2conda "grayskull>=3.1.0"
+        conda run --name pip2conda pip2conda \
             --all \
             --output environment.txt \
             --python-version ${{ matrix.python-version }}
         echo "-----------------"
         cat environment.txt
         echo "-----------------"
-        mamba install --quiet --yes --name test --file environment.txt
+        conda install --quiet --yes --name test --file environment.txt
 
     - name: Install PyOmicron
       run: python -m pip install --editable . --no-build-isolation -vv