diff --git a/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Control/Roslyn.SyntaxVisualizer.Control.csproj b/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Control/Roslyn.SyntaxVisualizer.Control.csproj
index f6261fa079..354a8a12bb 100644
--- a/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Control/Roslyn.SyntaxVisualizer.Control.csproj
+++ b/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Control/Roslyn.SyntaxVisualizer.Control.csproj
@@ -7,6 +7,8 @@
     <IsProductComponent>false</IsProductComponent>
     <UseWpf>true</UseWpf>
     <UseWindowsForms>true</UseWindowsForms>
+    <Nullable>enable</Nullable>
+    <LangVersion>9</LangVersion>
   </PropertyGroup>
 
   <!-- Package References -->
diff --git a/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Extension/Roslyn.SyntaxVisualizer.Extension.csproj b/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Extension/Roslyn.SyntaxVisualizer.Extension.csproj
index 03f01cead1..29453ba95c 100644
--- a/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Extension/Roslyn.SyntaxVisualizer.Extension.csproj
+++ b/src/VisualStudio.Roslyn.SDK/SyntaxVisualizer/Roslyn.SyntaxVisualizer.Extension/Roslyn.SyntaxVisualizer.Extension.csproj
@@ -7,6 +7,8 @@
     <EnableDefaultEmbeddedResourceItems>false</EnableDefaultEmbeddedResourceItems>
     <IsProductComponent>false</IsProductComponent>
     <UseWpf>true</UseWpf>
+    <Nullable>enable</Nullable>
+    <LangVersion>9</LangVersion>
 
     <!-- VSIX -->
     <CreateVsixContainer>false</CreateVsixContainer>