diff --git a/.github/workflows/dotnet-core.yml b/.github/workflows/dotnet-core.yml
index 2f2291f..6592fcc 100644
--- a/.github/workflows/dotnet-core.yml
+++ b/.github/workflows/dotnet-core.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        runs-on: [macOS-latest, ubuntu-latest, windows-latest]
+        runs-on: [macos-11, ubuntu-latest, windows-latest]
     name: ${{ matrix.runs-on }}
     runs-on: ${{ matrix.runs-on }}
     steps: