diff --git a/lib/pddlparse/include/pddlparse/ASTForward.h b/lib/pddlparse/include/pddlparse/ASTForward.h
index 15180db..107e5ee 100644
--- a/lib/pddlparse/include/pddlparse/ASTForward.h
+++ b/lib/pddlparse/include/pddlparse/ASTForward.h
@@ -127,6 +127,8 @@ using TermT = Variant<
 
 class Term : public detail::TermT
 {
+	Term() = delete;
+
 	using detail::TermT::TermT;
 };
 
@@ -143,6 +145,8 @@ using AtomicFormulaT = Variant<
 
 class AtomicFormula : public detail::AtomicFormulaT
 {
+	AtomicFormula() = delete;
+
 	using detail::AtomicFormulaT::AtomicFormulaT;
 };
 
@@ -165,6 +169,8 @@ using PreconditionT = Variant<
 
 class Precondition : public detail::PreconditionT
 {
+	Precondition() = delete;
+
 	using detail::PreconditionT::PreconditionT;
 };
 
@@ -185,6 +191,8 @@ using ConditionalEffectT = Variant<
 
 class ConditionalEffect : public detail::ConditionalEffectT
 {
+	ConditionalEffect() = delete;
+
 	using detail::ConditionalEffectT::ConditionalEffectT;
 };
 
@@ -205,6 +213,8 @@ using EffectT = Variant<
 
 class Effect : public detail::EffectT
 {
+	Effect() = delete;
+
 	using detail::EffectT::EffectT;
 };
 
@@ -219,6 +229,8 @@ using TypeT = Variant<
 
 class Type : public detail::TypeT
 {
+	Type() = delete;
+
 	using detail::TypeT::TypeT;
 };
 
@@ -233,6 +245,8 @@ using LiteralT = Variant<
 
 class Literal : public detail::LiteralT
 {
+	Literal() = delete;
+
 	using detail::LiteralT::LiteralT;
 };
 
@@ -251,6 +265,8 @@ using FactT = Variant<
 
 class Fact : public detail::FactT
 {
+	Fact() = delete;
+
 	using detail::FactT::FactT;
 };
 
diff --git a/lib/pddlparse/include/pddlparse/NormalizedASTForward.h b/lib/pddlparse/include/pddlparse/NormalizedASTForward.h
index 9183677..c2286b8 100644
--- a/lib/pddlparse/include/pddlparse/NormalizedASTForward.h
+++ b/lib/pddlparse/include/pddlparse/NormalizedASTForward.h
@@ -111,6 +111,8 @@ using AtomicFormulaT = Variant<
 
 class AtomicFormula : public detail::AtomicFormulaT
 {
+	AtomicFormula() = delete;
+
 	using detail::AtomicFormulaT::AtomicFormulaT;
 };
 
@@ -125,6 +127,8 @@ using LiteralT = Variant<
 
 class Literal : public detail::LiteralT
 {
+	Literal() = delete;
+
 	using detail::LiteralT::LiteralT;
 };
 
@@ -143,6 +147,8 @@ using PreconditionT = Variant<
 
 class Precondition : public detail::PreconditionT
 {
+	Precondition() = delete;
+
 	using detail::PreconditionT::PreconditionT;
 };
 
@@ -162,6 +168,8 @@ using DerivedPredicatePreconditionT = Variant<
 
 class DerivedPredicatePrecondition : public detail::DerivedPredicatePreconditionT
 {
+	DerivedPredicatePrecondition() = delete;
+
 	using detail::DerivedPredicatePreconditionT::DerivedPredicatePreconditionT;
 };
 
@@ -181,6 +189,8 @@ using ConditionalEffectT = Variant<
 
 class ConditionalEffect : public detail::ConditionalEffectT
 {
+	ConditionalEffect() = delete;
+
 	using detail::ConditionalEffectT::ConditionalEffectT;
 };
 
@@ -201,6 +211,8 @@ using EffectT = Variant<
 
 class Effect : public detail::EffectT
 {
+	Effect() = delete;
+
 	using detail::EffectT::EffectT;
 };