diff --git a/src/System.Management.Automation/engine/interpreter/ILightCallSiteBinder.cs b/src/System.Management.Automation/engine/interpreter/ILightCallSiteBinder.cs
index 49fbfdb0f8e..9f24d14fa14 100644
--- a/src/System.Management.Automation/engine/interpreter/ILightCallSiteBinder.cs
+++ b/src/System.Management.Automation/engine/interpreter/ILightCallSiteBinder.cs
@@ -13,6 +13,7 @@
  *
  * ***************************************************************************/
 
+#nullable enable
 #if !CLR2
 #else
 using Microsoft.Scripting.Ast;