diff --git a/include/plasp/pddl/expressions/PrimitiveType.h b/include/plasp/pddl/expressions/PrimitiveType.h
index 0001f0e..1c1fdd7 100644
--- a/include/plasp/pddl/expressions/PrimitiveType.h
+++ b/include/plasp/pddl/expressions/PrimitiveType.h
@@ -1,6 +1,7 @@
 #ifndef __PLASP__PDDL__EXPRESSION__PRIMITIVE_TYPE_H
 #define __PLASP__PDDL__EXPRESSION__PRIMITIVE_TYPE_H
 
+#include <plasp/pddl/ConsistencyException.h>
 #include <plasp/pddl/Expression.h>
 #include <plasp/pddl/Identifier.h>
 #include <plasp/utils/Parser.h>
@@ -25,8 +26,7 @@ class PrimitiveType: public Expression
 		static PrimitiveType *parseDeclaration(utils::Parser &parser, Context &context);
 		static void parseTypedDeclaration(utils::Parser &parser, Context &context);
 
-		template<class Container>
-		static PrimitiveType *parseExisting(utils::Parser &parser, Container &primitiveTypes);
+		static PrimitiveType *parseExisting(utils::Parser &parser, Context &context);
 
 		// TODO: method for lazy creation if not existing
 
@@ -38,6 +38,9 @@ class PrimitiveType: public Expression
 
 		bool isDeclared() const;
 
+	private:
+		static PrimitiveType *create(std::string name, Context &context);
+
 	private:
 		PrimitiveType();
 
@@ -56,50 +59,6 @@ class PrimitiveType: public Expression
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
-template<class Container>
-PrimitiveType *PrimitiveType::parseExisting(utils::Parser &parser,
-	Container &primitiveTypes)
-{
-	parser.skipWhiteSpace();
-
-	const auto typeName = parser.parseIdentifier(isIdentifier);
-
-	BOOST_ASSERT(!typeName.empty());
-
-	// TODO: use hash map
-	const auto match = std::find_if(primitiveTypes.cbegin(), primitiveTypes.cend(),
-		[&](const auto &primitiveType)
-		{
-			return primitiveType->name() == typeName;
-		});
-
-	if (match == primitiveTypes.cend())
-	{
-		// Allow implicit type "object"
-		if (typeName == "object")
-		{
-			auto objectType = std::make_unique<PrimitiveType>(PrimitiveType());
-			objectType->m_name = typeName;
-			objectType->setDirty(false);
-			objectType->setDeclared();
-
-			// TODO: make std::vector-independent
-			primitiveTypes.emplace_back(std::move(objectType));
-
-			return primitiveTypes.back().get();
-		}
-		else
-			throw utils::ParserException(parser.row(), parser.column(), "Primitive type \"" + typeName + "\" used but never declared");
-	}
-
-	auto *type = match->get();
-	type->setDirty();
-
-	return type;
-}
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-
 }
 }
 }
diff --git a/src/plasp/pddl/expressions/Constant.cpp b/src/plasp/pddl/expressions/Constant.cpp
index ec7f621..843bd28 100644
--- a/src/plasp/pddl/expressions/Constant.cpp
+++ b/src/plasp/pddl/expressions/Constant.cpp
@@ -65,7 +65,7 @@ void Constant::parseTypedDeclaration(utils::Parser &parser, Context &context)
 		return;
 
 	// If existing, parse and store parent type
-	auto *type = PrimitiveType::parseExisting(parser, context.primitiveTypes);
+	auto *type = PrimitiveType::parseExisting(parser, context);
 
 	// Assign parent type to all types that were previously flagged
 	std::for_each(context.constants.begin(), context.constants.end(),
diff --git a/src/plasp/pddl/expressions/PrimitiveType.cpp b/src/plasp/pddl/expressions/PrimitiveType.cpp
index cac8d8d..ad5f82f 100644
--- a/src/plasp/pddl/expressions/PrimitiveType.cpp
+++ b/src/plasp/pddl/expressions/PrimitiveType.cpp
@@ -26,6 +26,26 @@ PrimitiveType::PrimitiveType()
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+PrimitiveType *PrimitiveType::create(std::string name, Context &context)
+{
+	// Create new primitive type if not already existing
+	auto type = std::make_unique<PrimitiveType>(PrimitiveType());
+
+	type->m_name = name;
+
+	BOOST_ASSERT(!type->m_name.empty());
+
+	// Flag type for potentially upcoming parent type declaration
+	type->setDirty();
+
+	// TODO: Store constant in hash map
+	context.primitiveTypes.emplace_back(std::move(type));
+
+	return context.primitiveTypes.back().get();
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 PrimitiveType *PrimitiveType::parseDeclaration(utils::Parser &parser, Context &context)
 {
 	parser.skipWhiteSpace();
@@ -49,20 +69,7 @@ PrimitiveType *PrimitiveType::parseDeclaration(utils::Parser &parser, Context &c
 		return type;
 	}
 
-	// Create new primitive type if not already existing
-	auto type = std::make_unique<PrimitiveType>(PrimitiveType());
-
-	type->m_name = typeName;
-
-	BOOST_ASSERT(!type->m_name.empty());
-
-	// Flag type for potentially upcoming parent type declaration
-	type->setDirty();
-
-	// TODO: Store constant in hash map
-	context.primitiveTypes.emplace_back(std::move(type));
-
-	return context.primitiveTypes.back().get();
+	return create(typeName, context);
 }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -82,7 +89,7 @@ void PrimitiveType::parseTypedDeclaration(utils::Parser &parser, Context &contex
 		return;
 
 	// If existing, parse and store parent type
-	auto *parentType = parseExisting(parser, context.primitiveTypes);
+	auto *parentType = parseExisting(parser, context);
 
 	parentType->setDirty(false);
 
@@ -103,6 +110,38 @@ void PrimitiveType::parseTypedDeclaration(utils::Parser &parser, Context &contex
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
+PrimitiveType *PrimitiveType::parseExisting(utils::Parser &parser, Context &context)
+{
+	parser.skipWhiteSpace();
+
+	const auto typeName = parser.parseIdentifier(isIdentifier);
+
+	BOOST_ASSERT(!typeName.empty());
+
+	// TODO: use hash map
+	const auto match = std::find_if(context.primitiveTypes.cbegin(), context.primitiveTypes.cend(),
+		[&](const auto &primitiveType)
+		{
+			return primitiveType->name() == typeName;
+		});
+
+	if (match == context.primitiveTypes.cend())
+	{
+		// Primitive type "object" is implicitly declared
+		if (typeName != "object")
+			throw ConsistencyException("Primitive type \"" + typeName + "\" used but never declared");
+
+		return create(typeName, context);
+	}
+
+	auto *type = match->get();
+	type->setDirty();
+
+	return type;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
 void PrimitiveType::accept(plasp::pddl::ExpressionVisitor &expressionVisitor) const
 {
 	expressionVisitor.visit(*this);
diff --git a/src/plasp/pddl/expressions/Type.cpp b/src/plasp/pddl/expressions/Type.cpp
index 2aed578..4490828 100644
--- a/src/plasp/pddl/expressions/Type.cpp
+++ b/src/plasp/pddl/expressions/Type.cpp
@@ -18,7 +18,7 @@ namespace expressions
 
 ExpressionPointer parseExistingPrimitiveType(utils::Parser &parser, Context &context, const Variables &parameters)
 {
-	auto reference = std::make_unique<Reference<PrimitiveType>>(PrimitiveType::parseExisting(parser, context.primitiveTypes));
+	auto reference = std::make_unique<Reference<PrimitiveType>>(PrimitiveType::parseExisting(parser, context));
 
 	return reference;
 }
diff --git a/src/plasp/pddl/expressions/Variable.cpp b/src/plasp/pddl/expressions/Variable.cpp
index 384e943..e3bfd4e 100644
--- a/src/plasp/pddl/expressions/Variable.cpp
+++ b/src/plasp/pddl/expressions/Variable.cpp
@@ -94,7 +94,7 @@ void Variable::parseTypedDeclaration(utils::Parser &parser, Context &context, Va
 	}
 
 	// Parse primitive type
-	const auto *type = PrimitiveType::parseExisting(parser, context.primitiveTypes);
+	const auto *type = PrimitiveType::parseExisting(parser, context);
 
 	setType(type);
 }