diff --git a/src/plasp/pddl/Domain.cpp b/src/plasp/pddl/Domain.cpp
index d1492b3..c1cd60f 100644
--- a/src/plasp/pddl/Domain.cpp
+++ b/src/plasp/pddl/Domain.cpp
@@ -358,7 +358,7 @@ void Domain::checkConsistency()
 		const auto acceptType =
 			[&](const auto *type)
 			{
-				return ((type == nullptr) != hasRequirement(Requirement::Type::Typing));
+				return ((type == nullptr) != this->hasRequirement(Requirement::Type::Typing));
 			};
 
 		std::for_each(m_constants.cbegin(), m_constants.cend(),