diff --git a/tests/Avalonia.Base.UnitTests/Avalonia.Base.UnitTests.csproj b/tests/Avalonia.Base.UnitTests/Avalonia.Base.UnitTests.csproj
index d55dc8d544..c656801d90 100644
--- a/tests/Avalonia.Base.UnitTests/Avalonia.Base.UnitTests.csproj
+++ b/tests/Avalonia.Base.UnitTests/Avalonia.Base.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.Controls.UnitTests/Avalonia.Controls.UnitTests.csproj b/tests/Avalonia.Controls.UnitTests/Avalonia.Controls.UnitTests.csproj
index f8235f7d68..f7b63cdb75 100644
--- a/tests/Avalonia.Controls.UnitTests/Avalonia.Controls.UnitTests.csproj
+++ b/tests/Avalonia.Controls.UnitTests/Avalonia.Controls.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.Input.UnitTests/Avalonia.Input.UnitTests.csproj b/tests/Avalonia.Input.UnitTests/Avalonia.Input.UnitTests.csproj
index d35542b51f..8dd8faf9db 100644
--- a/tests/Avalonia.Input.UnitTests/Avalonia.Input.UnitTests.csproj
+++ b/tests/Avalonia.Input.UnitTests/Avalonia.Input.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.Interactivity.UnitTests/Avalonia.Interactivity.UnitTests.csproj b/tests/Avalonia.Interactivity.UnitTests/Avalonia.Interactivity.UnitTests.csproj
index 8f9607fe67..86c9cf0617 100644
--- a/tests/Avalonia.Interactivity.UnitTests/Avalonia.Interactivity.UnitTests.csproj
+++ b/tests/Avalonia.Interactivity.UnitTests/Avalonia.Interactivity.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\XUnit.props" />
diff --git a/tests/Avalonia.Layout.UnitTests/Avalonia.Layout.UnitTests.csproj b/tests/Avalonia.Layout.UnitTests/Avalonia.Layout.UnitTests.csproj
index af33c80352..0950856dca 100644
--- a/tests/Avalonia.Layout.UnitTests/Avalonia.Layout.UnitTests.csproj
+++ b/tests/Avalonia.Layout.UnitTests/Avalonia.Layout.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.Markup.UnitTests/Avalonia.Markup.UnitTests.csproj b/tests/Avalonia.Markup.UnitTests/Avalonia.Markup.UnitTests.csproj
index b7c4811495..3ccd3da044 100644
--- a/tests/Avalonia.Markup.UnitTests/Avalonia.Markup.UnitTests.csproj
+++ b/tests/Avalonia.Markup.UnitTests/Avalonia.Markup.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.Markup.Xaml.UnitTests/Avalonia.Markup.Xaml.UnitTests.csproj b/tests/Avalonia.Markup.Xaml.UnitTests/Avalonia.Markup.Xaml.UnitTests.csproj
index 0cbdc142eb..f6f8f6bcb0 100644
--- a/tests/Avalonia.Markup.Xaml.UnitTests/Avalonia.Markup.Xaml.UnitTests.csproj
+++ b/tests/Avalonia.Markup.Xaml.UnitTests/Avalonia.Markup.Xaml.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.Styling.UnitTests/Avalonia.Styling.UnitTests.csproj b/tests/Avalonia.Styling.UnitTests/Avalonia.Styling.UnitTests.csproj
index d35542b51f..8dd8faf9db 100644
--- a/tests/Avalonia.Styling.UnitTests/Avalonia.Styling.UnitTests.csproj
+++ b/tests/Avalonia.Styling.UnitTests/Avalonia.Styling.UnitTests.csproj
@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk" ToolsVersion="15.0">
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <Import Project="..\..\build\UnitTests.NetCore.targets" />
   <Import Project="..\..\build\Moq.props" />
diff --git a/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj b/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj
index 628ccb2a1f..c3957a71b9 100644
--- a/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj
+++ b/tests/Avalonia.UnitTests/Avalonia.UnitTests.csproj
@@ -2,6 +2,7 @@
   <PropertyGroup>
     <TargetFrameworks>net461;netcoreapp1.1</TargetFrameworks>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
+    <OutputType>Library</OutputType>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>