diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index edd96213..80c4970a 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -7,30 +7,24 @@ jobs:
     env:
       DOTNET_NOLOGO: true
     steps:
-    - uses: actions/checkout@v3
-    - uses: actions/setup-dotnet@v3
+    - uses: actions/checkout@v4.2.2
+    - uses: actions/setup-dotnet@v4.1.0
       with:
-        dotnet-version: |
-          3.1.x
-          6.0.x
+        dotnet-version: 9.0.x
     - run: dotnet restore src/NetMQ.sln
     - name: build 
       run: dotnet build src/NetMQ.sln /p:Configuration=Release /verbosity:minimal
-    - name: test netcoreapp3.1
-      run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f netcoreapp3.1 src/NetMQ.Tests/NetMQ.Tests.csproj
-    - name: test net6.0
-      run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f net6.0 src/NetMQ.Tests/NetMQ.Tests.csproj
+    - name: test net9.0
+      run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f net9.0 src/NetMQ.Tests/NetMQ.Tests.csproj
   windows:
     runs-on: windows-latest
     env:
       DOTNET_NOLOGO: true
     steps:
-    - uses: actions/checkout@v3
-    - uses: actions/setup-dotnet@v3
+    - uses: actions/checkout@v4.2.2
+    - uses: actions/setup-dotnet@v4.1.0
       with:
-        dotnet-version: |
-          3.1.x
-          6.0.x
+        dotnet-version: 9.0.x
     - name: Install codecov
       run: |
         choco install opencover.portable 
@@ -38,10 +32,8 @@ jobs:
     - run: dotnet restore src/NetMQ.sln
     - name: build 
       run: dotnet build src/NetMQ.sln /p:Configuration=Release /verbosity:minimal
-    - name: test net6.0
-      run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f net6.0 src\NetMQ.Tests\NetMQ.Tests.csproj
-    - name: test netcoreapp3.1
-      run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f netcoreapp3.1 src\NetMQ.Tests\NetMQ.Tests.csproj
+    - name: test net9.0
+      run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f net9.0 src\NetMQ.Tests\NetMQ.Tests.csproj
     - name: test net47
       run: dotnet test -v n -p:ParallelizeTestCollections=false --configuration Release --no-build -f net47 src\NetMQ.Tests\NetMQ.Tests.csproj
     - name: coverage
diff --git a/src/NetMQ.Tests/NetMQ.Tests.csproj b/src/NetMQ.Tests/NetMQ.Tests.csproj
index 5fe8a6bd..7f412ea6 100644
--- a/src/NetMQ.Tests/NetMQ.Tests.csproj
+++ b/src/NetMQ.Tests/NetMQ.Tests.csproj
@@ -7,7 +7,7 @@
     <PublicSign Condition=" '$(OS)' != 'Windows_NT' ">true</PublicSign>
     <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
     <IsTestProject>true</IsTestProject>
-    <TargetFrameworks>net6.0;netcoreapp3.1;net47</TargetFrameworks>
+    <TargetFrameworks>net9.0;net47</TargetFrameworks>
   </PropertyGroup>
 
   <PropertyGroup>