diff --git a/sandbox/BlazorApp/BlazorApp.csproj b/sandbox/BlazorApp/BlazorApp.csproj
index 74041af..173e196 100644
--- a/sandbox/BlazorApp/BlazorApp.csproj
+++ b/sandbox/BlazorApp/BlazorApp.csproj
@@ -3,6 +3,7 @@
     <PropertyGroup>
         <TargetFramework>net6.0</TargetFramework>
         <ImplicitUsings>enable</ImplicitUsings>
+        <IsPackable>false</IsPackable>
     </PropertyGroup>
 
     <ItemGroup>
diff --git a/sandbox/ConsoleApp/ConsoleApp.csproj b/sandbox/ConsoleApp/ConsoleApp.csproj
index 241e36b..9a761c6 100644
--- a/sandbox/ConsoleApp/ConsoleApp.csproj
+++ b/sandbox/ConsoleApp/ConsoleApp.csproj
@@ -5,6 +5,7 @@
         <TargetFramework>net6.0</TargetFramework>
         <LangVersion>10.0</LangVersion>
         <Nullable>enable</Nullable>
+        <IsPackable>false</IsPackable>
     </PropertyGroup>
 
     <ItemGroup>
diff --git a/sandbox/WpfApp/WpfApp.csproj b/sandbox/WpfApp/WpfApp.csproj
index d394da3..64c80a6 100644
--- a/sandbox/WpfApp/WpfApp.csproj
+++ b/sandbox/WpfApp/WpfApp.csproj
@@ -5,6 +5,7 @@
     <TargetFramework>net6.0-windows</TargetFramework>
     <Nullable>enable</Nullable>
     <UseWPF>true</UseWPF>
+    <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/ObservableCollections/ObservableCollections.csproj b/src/ObservableCollections/ObservableCollections.csproj
index 0ad6220..c5d263e 100644
--- a/src/ObservableCollections/ObservableCollections.csproj
+++ b/src/ObservableCollections/ObservableCollections.csproj
@@ -10,6 +10,7 @@
         <PackageTags>collection</PackageTags>
         <Description>High performance observable collections and synchronized views, for WPF, Blazor, Unity.</Description>
         <SignAssembly>true</SignAssembly>
+        <IsPackable>true</IsPackable>
     </PropertyGroup>
 
     <ItemGroup Condition="$(TargetFramework) == 'netstandard2.0'">
diff --git a/tools/PostBuildUtility/PostBuildUtility.csproj b/tools/PostBuildUtility/PostBuildUtility.csproj
index 94830bc..d96d8d5 100644
--- a/tools/PostBuildUtility/PostBuildUtility.csproj
+++ b/tools/PostBuildUtility/PostBuildUtility.csproj
@@ -4,6 +4,7 @@
         <OutputType>Exe</OutputType>
         <TargetFramework>net6.0</TargetFramework>
         <Nullable>enable</Nullable>
+        <IsPackable>false</IsPackable>
     </PropertyGroup>
 
     <ItemGroup>