diff --git a/result/dotnet/Result/Result.csproj b/result/dotnet/Result/Result.csproj
index c004a55..d48265f 100644
--- a/result/dotnet/Result/Result.csproj
+++ b/result/dotnet/Result/Result.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/vote/dotnet/Vote/Vote.csproj b/vote/dotnet/Vote/Vote.csproj
index 479b76e..3a80a2a 100644
--- a/vote/dotnet/Vote/Vote.csproj
+++ b/vote/dotnet/Vote/Vote.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/worker/dotnet/Worker/Worker.csproj b/worker/dotnet/Worker/Worker.csproj
index 46ec2db..d85a98c 100644
--- a/worker/dotnet/Worker/Worker.csproj
+++ b/worker/dotnet/Worker/Worker.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/worker/src/Worker/Worker.csproj b/worker/src/Worker/Worker.csproj
index 03d43df..88e9a90 100644
--- a/worker/src/Worker/Worker.csproj
+++ b/worker/src/Worker/Worker.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>