diff --git a/src/tools/illink/src/ILLink.Tasks/build/Microsoft.NET.ILLink.targets b/src/tools/illink/src/ILLink.Tasks/build/Microsoft.NET.ILLink.targets
index 4ae285b0250f5..9c23d0ee20d7e 100644
--- a/src/tools/illink/src/ILLink.Tasks/build/Microsoft.NET.ILLink.targets
+++ b/src/tools/illink/src/ILLink.Tasks/build/Microsoft.NET.ILLink.targets
@@ -44,6 +44,7 @@ Copyright (c) .NET Foundation. All rights reserved.
     <_EnableConsumingManagedCodeFromNativeHosting Condition="'$(EnableCppCLIHostActivation)' == 'true'">true</_EnableConsumingManagedCodeFromNativeHosting>
     <_EnableConsumingManagedCodeFromNativeHosting Condition="'$(_EnableConsumingManagedCodeFromNativeHosting)' == ''">false</_EnableConsumingManagedCodeFromNativeHosting>
     <VerifyDependencyInjectionOpenGenericServiceTrimmability Condition="'$(VerifyDependencyInjectionOpenGenericServiceTrimmability)' == ''">true</VerifyDependencyInjectionOpenGenericServiceTrimmability>
+    <JsonSerializerIsReflectionEnabledByDefault Condition="'$(JsonSerializerIsReflectionEnabledByDefault)' == ''">false</JsonSerializerIsReflectionEnabledByDefault>
   </PropertyGroup>