diff --git a/libsolidity/ast/TypeProvider.cpp b/libsolidity/ast/TypeProvider.cpp
index ee7a65004..6183493b4 100644
--- a/libsolidity/ast/TypeProvider.cpp
+++ b/libsolidity/ast/TypeProvider.cpp
@@ -578,3 +578,8 @@ MappingType const* TypeProvider::mapping(Type const* _keyType, Type const* _valu
 {
 	return createAndGet<MappingType>(_keyType, _valueType);
 }
+
+UserDefinedValueType const* TypeProvider::userDefinedValueType(UserDefinedValueTypeDefinition const& _definition)
+{
+	return createAndGet<UserDefinedValueType>(_definition);
+}
diff --git a/libsolidity/ast/TypeProvider.h b/libsolidity/ast/TypeProvider.h
index 6cdfdadc6..78b8378ca 100644
--- a/libsolidity/ast/TypeProvider.h
+++ b/libsolidity/ast/TypeProvider.h
@@ -201,6 +201,8 @@ public:
 
 	static MappingType const* mapping(Type const* _keyType, Type const* _valueType);
 
+	static UserDefinedValueType const* userDefinedValueType(UserDefinedValueTypeDefinition const& _definition);
+
 private:
 	/// Global TypeProvider instance.
 	static TypeProvider& instance()
diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 0fe9a728f..c1163156a 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -2533,6 +2533,36 @@ unsigned EnumType::memberValue(ASTString const& _member) const
 	solAssert(false, "Requested unknown enum value " + _member);
 }
 
+Type const& UserDefinedValueType::underlyingType() const
+{
+	Type const* type = m_definition.underlyingType()->annotation().type;
+	solAssert(type, "");
+	return *type;
+}
+
+string UserDefinedValueType::richIdentifier() const
+{
+	return "t_userDefinedValueType" + parenthesizeIdentifier(m_definition.name()) + to_string(m_definition.id());
+}
+
+bool UserDefinedValueType::operator==(Type const& _other) const
+{
+	if (_other.category() != category())
+		return false;
+	UserDefinedValueType const& other = dynamic_cast<UserDefinedValueType const&>(_other);
+	return other.definition() == definition();
+}
+
+string UserDefinedValueType::toString(bool /* _short */) const
+{
+	return "user defined type " + definition().name();
+}
+
+vector<tuple<string, Type const*>> UserDefinedValueType::makeStackItems() const
+{
+	return underlyingType().stackItems();
+}
+
 BoolResult TupleType::isImplicitlyConvertibleTo(Type const& _other) const
 {
 	if (auto tupleType = dynamic_cast<TupleType const*>(&_other))
@@ -2884,6 +2914,8 @@ string FunctionType::richIdentifier() const
 	case Kind::GasLeft: id += "gasleft"; break;
 	case Kind::Event: id += "event"; break;
 	case Kind::Error: id += "error"; break;
+	case Kind::Wrap: id += "wrap"; break;
+	case Kind::Unwrap: id += "unwrap"; break;
 	case Kind::SetGas: id += "setgas"; break;
 	case Kind::SetValue: id += "setvalue"; break;
 	case Kind::BlockHash: id += "blockhash"; break;
@@ -3754,6 +3786,34 @@ MemberList::MemberMap TypeType::nativeMembers(ASTNode const* _currentScope) cons
 		for (ASTPointer<EnumValue> const& enumValue: enumDef.members())
 			members.emplace_back(enumValue.get(), enumType);
 	}
+	else if (m_actualType->category() == Category::UserDefinedValueType)
+	{
+		auto& userDefined = dynamic_cast<UserDefinedValueType const&>(*m_actualType);
+		members.emplace_back(
+			"wrap",
+			TypeProvider::function(
+				TypePointers{&userDefined.underlyingType()},
+				TypePointers{&userDefined},
+				strings{string{}},
+				strings{string{}},
+				FunctionType::Kind::Wrap,
+				false, /*_arbitraryParameters */
+				StateMutability::Pure
+			)
+		);
+		members.emplace_back(
+			"unwrap",
+			TypeProvider::function(
+				TypePointers{&userDefined},
+				TypePointers{&userDefined.underlyingType()},
+				strings{string{}},
+				strings{string{}},
+				FunctionType::Kind::Unwrap,
+				false, /* _arbitraryParameters */
+				StateMutability::Pure
+			)
+		);
+	}
 	else if (
 		auto const* arrayType = dynamic_cast<ArrayType const*>(m_actualType);
 		arrayType && arrayType->isByteArray()
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index 57f5201f6..b092628fb 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -174,7 +174,7 @@ public:
 	enum class Category
 	{
 		Address, Integer, RationalNumber, StringLiteral, Bool, FixedPoint, Array, ArraySlice,
-		FixedBytes, Contract, Struct, Function, Enum, Tuple,
+		FixedBytes, Contract, Struct, Function, Enum, UserDefinedValueType, Tuple,
 		Mapping, TypeType, Modifier, Magic, Module,
 		InaccessibleDynamic
 	};
@@ -1082,6 +1082,53 @@ private:
 	EnumDefinition const& m_enum;
 };
 
+/**
+ * The type of a UserDefinedValueType.
+ */
+class UserDefinedValueType: public Type
+{
+public:
+	explicit UserDefinedValueType(UserDefinedValueTypeDefinition const& _definition):
+		m_definition(_definition)
+	{}
+
+	Category category() const override { return Category::UserDefinedValueType; }
+	Type const& underlyingType() const;
+	UserDefinedValueTypeDefinition const& definition() const { return m_definition; }
+
+	TypeResult binaryOperatorResult(Token, Type const*) const override { return nullptr; }
+	Type const* encodingType() const override { return &underlyingType(); }
+	TypeResult interfaceType(bool /* _inLibrary */) const override {return &underlyingType(); }
+	std::string richIdentifier() const override;
+	bool operator==(Type const& _other) const override;
+
+	unsigned calldataEncodedSize(bool _padded) const override { return underlyingType().calldataEncodedSize(_padded); }
+
+	bool leftAligned() const override { return underlyingType().leftAligned(); }
+	bool canBeStored() const override { return underlyingType().canBeStored(); }
+	u256 storageSize() const override { return underlyingType().storageSize(); }
+	bool isValueType() const override
+	{
+		solAssert(underlyingType().isValueType(), "");
+		return true;
+	}
+	bool nameable() const override
+	{
+		solAssert(underlyingType().nameable(), "");
+		return true;
+	}
+
+	std::string toString(bool _short) const override;
+	std::string canonicalName() const override { solAssert(false, ""); }
+	std::string signatureInExternalFunction(bool) const override { solAssert(false, ""); }
+
+protected:
+	std::vector<std::tuple<std::string, Type const*>> makeStackItems() const override;
+
+private:
+	UserDefinedValueTypeDefinition const& m_definition;
+};
+
 /**
  * Type that can hold a finite sequence of values of different types.
  * In some cases, the components are empty pointers (when used as placeholders).
@@ -1150,6 +1197,8 @@ public:
 		RIPEMD160, ///< CALL to special contract for ripemd160
 		Event, ///< syntactic sugar for LOG*
 		Error, ///< creating an error instance in revert or require
+		Wrap, ///< customType.wrap(...) for user defined value types
+		Unwrap, ///< customType.unwrap(...) for user defined value types
 		SetGas, ///< modify the default gas value for the function call
 		SetValue, ///< modify the default value transfer for the function call
 		BlockHash, ///< BLOCKHASH