diff --git a/src/plasp/pddl/TranslatorASP.cpp b/src/plasp/pddl/TranslatorASP.cpp
index 878a7d7..801429b 100644
--- a/src/plasp/pddl/TranslatorASP.cpp
+++ b/src/plasp/pddl/TranslatorASP.cpp
@@ -212,7 +212,7 @@ void TranslatorASP::translateActions() const
 
 					// TODO: implement conditional effects
 					if (enumerateEffects)
-						m_outputStream << ", " << utils::Keyword("effect") << "(unconditional)";
+						m_outputStream << ", " << utils::Keyword("effect") << "(" << utils::Keyword("unconditional") << ")";
 
 					m_outputStream << ", ";
 
diff --git a/src/plasp/sas/TranslatorASP.cpp b/src/plasp/sas/TranslatorASP.cpp
index 8ce1dde..63eb9b5 100644
--- a/src/plasp/sas/TranslatorASP.cpp
+++ b/src/plasp/sas/TranslatorASP.cpp
@@ -188,7 +188,7 @@ void TranslatorASP::translateActions() const
 					operator_.printPredicateAsASP(m_outputStream);
 
 					if (conditions.empty())
-						m_outputStream << ", " << utils::Keyword("effect") << "(unconditional), ";
+						m_outputStream << ", " << utils::Keyword("effect") << "(" << utils::Keyword("unconditional") << "), ";
 					else
 					{
 						m_outputStream << ", " << utils::Keyword("effect") << "(" << utils::Number(std::to_string(currentEffectID)) << "), ";
@@ -286,7 +286,7 @@ void TranslatorASP::translateAxiomRules() const
 			m_outputStream
 				<< utils::Keyword("postcondition") << "("
 				<< utils::Keyword("axiomRule") << "(" << utils::Number(axiomRuleID) << "), "
-				<< utils::Keyword("effect") << "(unconditional), ";
+				<< utils::Keyword("effect") << "(" << utils::Keyword("unconditional") << "), ";
 			postcondition.variable().printNameAsASPPredicate(m_outputStream);
 			m_outputStream << ", ";
 			postcondition.value().printAsASPPredicate(m_outputStream);