diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d20ae9e7..d02240d6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,7 +31,9 @@ jobs:
       - name: Setup .NET SDK
         uses: actions/setup-dotnet@v4.1.0
         with:
-          dotnet-version: 8.0.x
+          dotnet-version: |
+            9.0.x
+            8.0.x
       - name: Build
         run: dotnet build src --configuration Release
       - name: Upload packages
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 0ad606c1..5a22df32 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -20,7 +20,7 @@ jobs:
       - name: Setup .NET SDK
         uses: actions/setup-dotnet@v4.1.0
         with:
-          dotnet-version: 8.0.x
+          dotnet-version: 9.0.x
       - name: Build
         run: dotnet build src --configuration Release
       - name: Sign NuGet packages
diff --git a/global.json b/global.json
index 2134ed94..d5bf446d 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "8.0.400",
+    "version": "9.0.100",
     "rollForward": "latestFeature"
   }
 }
\ No newline at end of file
diff --git a/src/NServiceBus.Storage.MongoDB.AcceptanceTests/NServiceBus.Storage.MongoDB.AcceptanceTests.csproj b/src/NServiceBus.Storage.MongoDB.AcceptanceTests/NServiceBus.Storage.MongoDB.AcceptanceTests.csproj
index 049776a0..7042cf3e 100644
--- a/src/NServiceBus.Storage.MongoDB.AcceptanceTests/NServiceBus.Storage.MongoDB.AcceptanceTests.csproj
+++ b/src/NServiceBus.Storage.MongoDB.AcceptanceTests/NServiceBus.Storage.MongoDB.AcceptanceTests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests.csproj b/src/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests.csproj
index 7aedce30..5e943773 100644
--- a/src/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests.csproj
+++ b/src/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests/NServiceBus.Storage.MongoDB.NoTx.AcceptanceTests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/NServiceBus.Storage.MongoDB.PersistenceTests/NServiceBus.Storage.MongoDB.PersistenceTests.csproj b/src/NServiceBus.Storage.MongoDB.PersistenceTests/NServiceBus.Storage.MongoDB.PersistenceTests.csproj
index 11714b35..4f90367a 100644
--- a/src/NServiceBus.Storage.MongoDB.PersistenceTests/NServiceBus.Storage.MongoDB.PersistenceTests.csproj
+++ b/src/NServiceBus.Storage.MongoDB.PersistenceTests/NServiceBus.Storage.MongoDB.PersistenceTests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/NServiceBus.Storage.MongoDB.Tests/NServiceBus.Storage.MongoDB.Tests.csproj b/src/NServiceBus.Storage.MongoDB.Tests/NServiceBus.Storage.MongoDB.Tests.csproj
index 505aa69f..cee5b5f7 100644
--- a/src/NServiceBus.Storage.MongoDB.Tests/NServiceBus.Storage.MongoDB.Tests.csproj
+++ b/src/NServiceBus.Storage.MongoDB.Tests/NServiceBus.Storage.MongoDB.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests.csproj b/src/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests.csproj
index e9be4788..7f702871 100644
--- a/src/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests.csproj
+++ b/src/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests/NServiceBus.Storage.MongoDB.TransactionalSession.AcceptanceTests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
     <!-- We want the root namespace to match the transactional session one -->
     <RootNamespace>NServiceBus.TransactionalSession.AcceptanceTests</RootNamespace>
   </PropertyGroup>
diff --git a/src/NServiceBus.Storage.MongoDB.TransactionalSession.Tests/NServiceBus.Storage.MongoDB.TransactionalSession.Tests.csproj b/src/NServiceBus.Storage.MongoDB.TransactionalSession.Tests/NServiceBus.Storage.MongoDB.TransactionalSession.Tests.csproj
index 7b79eece..8702885d 100644
--- a/src/NServiceBus.Storage.MongoDB.TransactionalSession.Tests/NServiceBus.Storage.MongoDB.TransactionalSession.Tests.csproj
+++ b/src/NServiceBus.Storage.MongoDB.TransactionalSession.Tests/NServiceBus.Storage.MongoDB.TransactionalSession.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>