Index: src/GenPoly/Box.cpp
===================================================================
--- src/GenPoly/Box.cpp	(revision f979f0ba3e91f53f961ddfb6b75fd4b82f468087)
+++ src/GenPoly/Box.cpp	(revision 35cc6d4773c9705fbac2d875d39d6aa6120e8f80)
@@ -86,9 +86,11 @@
 			makeLayoutCType()
 		) );
-		params.emplace_back( new ast::ObjectDecl(
+		auto alignParam = new ast::ObjectDecl(
 			sizedParam->location,
 			alignofName( paramName ),
 			makeLayoutCType()
-		) );
+		);
+		alignParam->attributes.push_back( new ast::Attribute( "unused" ) );
+		params.emplace_back( alignParam );
 	}
 }