diff --git a/Jellyfin.Api/Jellyfin.Api.csproj b/Jellyfin.Api/Jellyfin.Api.csproj
index 25d5d0c89..a8de171cc 100644
--- a/Jellyfin.Api/Jellyfin.Api.csproj
+++ b/Jellyfin.Api/Jellyfin.Api.csproj
@@ -9,6 +9,7 @@
     <TargetFramework>netstandard2.1</TargetFramework>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/Jellyfin.Api/Models/StartupDtos/StartupConfigurationDto.cs b/Jellyfin.Api/Models/StartupDtos/StartupConfigurationDto.cs
index d048dad0a..5a83a030d 100644
--- a/Jellyfin.Api/Models/StartupDtos/StartupConfigurationDto.cs
+++ b/Jellyfin.Api/Models/StartupDtos/StartupConfigurationDto.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace Jellyfin.Api.Models.StartupDtos
 {
     /// <summary>
diff --git a/Jellyfin.Api/Models/StartupDtos/StartupUserDto.cs b/Jellyfin.Api/Models/StartupDtos/StartupUserDto.cs
index 3a9348037..0dbb245ec 100644
--- a/Jellyfin.Api/Models/StartupDtos/StartupUserDto.cs
+++ b/Jellyfin.Api/Models/StartupDtos/StartupUserDto.cs
@@ -1,3 +1,5 @@
+#nullable disable
+
 namespace Jellyfin.Api.Models.StartupDtos
 {
     /// <summary>
diff --git a/Jellyfin.Data/Jellyfin.Data.csproj b/Jellyfin.Data/Jellyfin.Data.csproj
index 9157c3ead..c2c105917 100644
--- a/Jellyfin.Data/Jellyfin.Data.csproj
+++ b/Jellyfin.Data/Jellyfin.Data.csproj
@@ -4,6 +4,7 @@
     <TargetFrameworks>netstandard2.0;netstandard2.1</TargetFrameworks>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
+    <TreatWarningsAsErrors Condition=" '$(Configuration)' == 'Release' ">true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
diff --git a/RSSDP/RSSDP.csproj b/RSSDP/RSSDP.csproj
index e3f3127b6..553693171 100644
--- a/RSSDP/RSSDP.csproj
+++ b/RSSDP/RSSDP.csproj
@@ -14,6 +14,7 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.1</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
 </Project>