diff --git a/dotnet/src/InternalUtilities/src/Schema/JsonSchemaMapper.ReflectionHelpers.cs b/dotnet/src/InternalUtilities/src/Schema/JsonSchemaMapper.ReflectionHelpers.cs
index 31c582756e66..11dc0c6d85b7 100644
--- a/dotnet/src/InternalUtilities/src/Schema/JsonSchemaMapper.ReflectionHelpers.cs
+++ b/dotnet/src/InternalUtilities/src/Schema/JsonSchemaMapper.ReflectionHelpers.cs
@@ -25,7 +25,7 @@ static partial class JsonSchemaMapper
     private static Type GetElementType(JsonTypeInfo typeInfo)
     {
         Debug.Assert(typeInfo.Kind is JsonTypeInfoKind.Enumerable or JsonTypeInfoKind.Dictionary);
-        return (Type)typeof(JsonTypeInfo).GetProperty("ElementType", BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(typeInfo)!;
+        return (Type)typeof(JsonTypeInfo).GetProperty("ElementType", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)?.GetValue(typeInfo)!;
     }
 
     // The source generator currently doesn't populate attribute providers for properties