diff --git a/.github/workflows/build-frontends.yml b/.github/workflows/build-frontends.yml
index deab3b280..c97455c64 100644
--- a/.github/workflows/build-frontends.yml
+++ b/.github/workflows/build-frontends.yml
@@ -18,7 +18,7 @@ jobs:
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.x
+        dotnet-version: 3.1.x
     - name: Install dependencies
       run: dotnet restore Frontends.sln
     - name: Build
diff --git a/.github/workflows/build-ilspy.yml b/.github/workflows/build-ilspy.yml
index 7804334c3..9a68f2bba 100644
--- a/.github/workflows/build-ilspy.yml
+++ b/.github/workflows/build-ilspy.yml
@@ -43,10 +43,6 @@ jobs:
       uses: actions/setup-dotnet@v1
       with:
         dotnet-version: '3.1.x'
-    - name: Setup .NET 5.0
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: '5.0.x'
 
     - name: Add msbuild to PATH
       uses: microsoft/setup-msbuild@v1.0.2
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index ba9f6c8ec..7965ef64c 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -30,7 +30,7 @@ jobs:
     - name: Setup .NET Core
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.x
+        dotnet-version: 3.1.x
     - name: Build
       run: dotnet build Frontends.sln --configuration Release
 
diff --git a/global.json b/global.json
index 7a808732b..9f0fa0bd9 100644
--- a/global.json
+++ b/global.json
@@ -3,7 +3,7 @@
 		"MSBuild.Sdk.Extras": "2.0.54"
 	},
 	"sdk": {
-		"version": "5.0.100",
+		"version": "3.1.100",
 		"rollForward": "latestFeature"
 	}
 }