diff --git a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
index 3af7868a176f8..522cea0c61ca2 100644
--- a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
+++ b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
@@ -3,5 +3,8 @@
     <type fullname="System.Globalization.GlobalizationMode">
       <method signature="System.Boolean get_Invariant()" body="stub" value="true" feature="System.Globalization.Invariant" featurevalue="true" />
     </type>
+    <type fullname="System.LocalAppContextSwitches">
+      <method signature="System.Boolean get_EnableUnsafeUTF7Encoding()" body="stub" value="true" feature="System.Text.Encoding.EnableUnsafeUTF7Encoding" featurevalue="true" />
+    </type>
   </assembly>
 </linker>