diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index cd57ed263..4bb17304f 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -35,6 +35,14 @@ jobs:
       with:
         version: "1.8.27"
 
+    - name: Set up .NET (required by mikeio1d, see networks group)
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '8.0.x'
+
+    - name: Remove newer .NET runtimes so mikeio1d doesn't roll forward off 8.0
+      run: sudo rm -rf /usr/share/dotnet/shared/Microsoft.NETCore.App/9.* /usr/share/dotnet/shared/Microsoft.NETCore.App/10.*
+
     - name: Install dependencies
       run: uv sync --group dev --group docs --group networks
 
diff --git a/.github/workflows/full_test.yml b/.github/workflows/full_test.yml
index c20ff88f0..c58ff7654 100644
--- a/.github/workflows/full_test.yml
+++ b/.github/workflows/full_test.yml
@@ -37,6 +37,14 @@ jobs:
           python-version: ${{ matrix.python-version }}
           enable-cache: true
 
+      - name: Set up .NET (required by mikeio1d, see networks group)
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '8.0.x'
+
+      - name: Remove newer .NET runtimes so mikeio1d doesn't roll forward off 8.0
+        run: sudo rm -rf /usr/share/dotnet/shared/Microsoft.NETCore.App/9.* /usr/share/dotnet/shared/Microsoft.NETCore.App/10.*
+
       - name: Install dependencies
         run: uv sync --group test --group networks --no-dev
 
diff --git a/.github/workflows/notebooks_test.yml b/.github/workflows/notebooks_test.yml
index dd64a1df6..ab10f10c7 100644
--- a/.github/workflows/notebooks_test.yml
+++ b/.github/workflows/notebooks_test.yml
@@ -20,6 +20,12 @@ jobs:
       with:
         python-version: "3.14"
         enable-cache: true
+    - name: Set up .NET (required by mikeio1d, see networks group)
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: '8.0.x'
+    - name: Remove newer .NET runtimes so mikeio1d doesn't roll forward off 8.0
+      run: sudo rm -rf /usr/share/dotnet/shared/Microsoft.NETCore.App/9.* /usr/share/dotnet/shared/Microsoft.NETCore.App/10.*
     - name: Install dependencies
       run: uv sync --group test --group notebooks --group networks --no-dev
     - name: Test notebooks