diff --git a/include/plasp/pddl/Problem.h b/include/plasp/pddl/Problem.h
index c731853..d21b40f 100644
--- a/include/plasp/pddl/Problem.h
+++ b/include/plasp/pddl/Problem.h
@@ -45,6 +45,8 @@ class Problem
 
 		void checkConsistency();
 
+		void normalize();
+
 	private:
 		void parseRequirementSection();
 		void computeDerivedRequirements();
diff --git a/src/plasp/pddl/Description.cpp b/src/plasp/pddl/Description.cpp
index 6d577ff..83672ae 100644
--- a/src/plasp/pddl/Description.cpp
+++ b/src/plasp/pddl/Description.cpp
@@ -207,6 +207,9 @@ void Description::checkConsistency()
 void Description::normalize()
 {
 	m_domain->normalize();
+
+	if (m_problem)
+		m_problem->normalize();
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/src/plasp/pddl/Problem.cpp b/src/plasp/pddl/Problem.cpp
index 8a2799e..9f38d69 100644
--- a/src/plasp/pddl/Problem.cpp
+++ b/src/plasp/pddl/Problem.cpp
@@ -395,5 +395,16 @@ void Problem::checkConsistency()
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+void Problem::normalize()
+{
+	BOOST_ASSERT(m_goal);
+
+	// TODO: normalize objects and initial state
+
+	m_goal->normalize();
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 }
 }