diff --git a/test/porousmediumflow/1p/implicit/incompressible/problem.hh b/test/porousmediumflow/1p/implicit/incompressible/problem.hh
index bbd669643f675599b4ff300547b851c2817c9558..cf51ae7517972d8124bb50a78c94188cfbdb464a 100644
--- a/test/porousmediumflow/1p/implicit/incompressible/problem.hh
+++ b/test/porousmediumflow/1p/implicit/incompressible/problem.hh
@@ -94,6 +94,7 @@ struct EnableFVGridGeometryCache<TypeTag, TTag::OnePIncompressible> { static con
 
 // define a TypeTag for a quad precision test
 #if HAVE_QUAD
+namespace TTag {
 struct OnePIncompressibleTpfaQuad { using InheritsFrom = std::tuple<OnePIncompressibleTpfa>; };
 } // end namespace TTag
 template<class TypeTag>