diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative.Mcp/Microsoft.Agents.AI.Workflows.Declarative.Mcp.csproj b/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative.Mcp/Microsoft.Agents.AI.Workflows.Declarative.Mcp.csproj
index e6089fc028..5738db4860 100644
--- a/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative.Mcp/Microsoft.Agents.AI.Workflows.Declarative.Mcp.csproj
+++ b/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative.Mcp/Microsoft.Agents.AI.Workflows.Declarative.Mcp.csproj
@@ -13,9 +13,11 @@
 
   <Import Project="$(RepoRoot)/dotnet/nuget/nuget-package.props" />
 
-  <!-- Package not yet published to NuGet — disable baseline validation until first release -->
+  <!-- First GA after the RC milestone. Baseline against the latest published RC so package
+       validation catches accidental breaking changes between RC and GA. Future GAs should
+       bump this to the previous GA version. -->
   <PropertyGroup>
-    <EnablePackageValidation>false</EnablePackageValidation>
+    <PackageValidationBaselineVersion>1.8.0-rc1</PackageValidationBaselineVersion>
   </PropertyGroup>
 
   <PropertyGroup>
diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Microsoft.Agents.AI.Workflows.Declarative.csproj b/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Microsoft.Agents.AI.Workflows.Declarative.csproj
index 9842a02c4a..5764540979 100644
--- a/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Microsoft.Agents.AI.Workflows.Declarative.csproj
+++ b/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/Microsoft.Agents.AI.Workflows.Declarative.csproj
@@ -13,10 +13,11 @@
 
   <Import Project="$(RepoRoot)/dotnet/nuget/nuget-package.props" />
 
-  <!-- disable baseline validation until first release -->
+  <!-- First GA after the RC milestone. Baseline against the latest published RC so package
+       validation catches accidental breaking changes between RC and GA. Future GAs should
+       bump this to the previous GA version. -->
   <PropertyGroup>
-    <PackageValidationBaselineVersion />
-    <EnablePackageValidation>false</EnablePackageValidation>
+    <PackageValidationBaselineVersion>1.8.0-rc1</PackageValidationBaselineVersion>
   </PropertyGroup>
 
   <PropertyGroup>