diff --git a/libsolidity/ast/Types.cpp b/libsolidity/ast/Types.cpp
index 971e1f184..dbabc8db5 100644
--- a/libsolidity/ast/Types.cpp
+++ b/libsolidity/ast/Types.cpp
@@ -2512,24 +2512,6 @@ FunctionTypePointer FunctionType::asMemberFunction(bool _inLibrary, bool _bound)
 	);
 }
 
-vector<string> const FunctionType::parameterTypeNames(bool _addDataLocation) const
-{
-	vector<string> names;
-	for (TypePointer const& t: parameterTypes())
-		names.push_back(t->canonicalName(_addDataLocation));
-
-	return names;
-}
-
-vector<string> const FunctionType::returnParameterTypeNames(bool _addDataLocation) const
-{
-	vector<string> names;
-	for (TypePointer const& t: m_returnParameterTypes)
-		names.push_back(t->canonicalName(_addDataLocation));
-
-	return names;
-}
-
 TypePointer const& FunctionType::selfType() const
 {
 	solAssert(bound(), "Function is not bound.");
diff --git a/libsolidity/ast/Types.h b/libsolidity/ast/Types.h
index 770cbb300..a5147f176 100644
--- a/libsolidity/ast/Types.h
+++ b/libsolidity/ast/Types.h
@@ -915,10 +915,8 @@ public:
 
 	TypePointers parameterTypes() const;
 	std::vector<std::string> parameterNames() const;
-	std::vector<std::string> const parameterTypeNames(bool _addDataLocation) const;
 	TypePointers const& returnParameterTypes() const { return m_returnParameterTypes; }
 	std::vector<std::string> const& returnParameterNames() const { return m_returnParameterNames; }
-	std::vector<std::string> const returnParameterTypeNames(bool _addDataLocation) const;
 	/// @returns the "self" parameter type for a bound function
 	TypePointer const& selfType() const;
 
diff --git a/libsolidity/interface/InterfaceHandler.cpp b/libsolidity/interface/InterfaceHandler.cpp
index 9944bb22d..6c1bb0c4d 100644
--- a/libsolidity/interface/InterfaceHandler.cpp
+++ b/libsolidity/interface/InterfaceHandler.cpp
@@ -30,20 +30,6 @@ Json::Value InterfaceHandler::abiInterface(ContractDefinition const& _contractDe
 {
 	Json::Value abi(Json::arrayValue);
 
-	auto populateParameters = [](vector<string> const& _paramNames, vector<string> const& _paramTypes)
-	{
-		Json::Value params(Json::arrayValue);
-		solAssert(_paramNames.size() == _paramTypes.size(), "Names and types vector size does not match");
-		for (unsigned i = 0; i < _paramNames.size(); ++i)
-		{
-			Json::Value param;
-			param["name"] = _paramNames[i];
-			param["type"] = _paramTypes[i];
-			params.append(param);
-		}
-		return params;
-	};
-
 	for (auto it: _contractDef.interfaceFunctions())
 	{
 		auto externalFunctionType = it.second->interfaceFunctionType();
@@ -52,13 +38,15 @@ Json::Value InterfaceHandler::abiInterface(ContractDefinition const& _contractDe
 		method["name"] = it.second->declaration().name();
 		method["constant"] = it.second->isConstant();
 		method["payable"] = it.second->isPayable();
-		method["inputs"] = populateParameters(
+		method["inputs"] = formatTypeList(
 			externalFunctionType->parameterNames(),
-			externalFunctionType->parameterTypeNames(_contractDef.isLibrary())
+			externalFunctionType->parameterTypes(),
+			_contractDef.isLibrary()
 		);
-		method["outputs"] = populateParameters(
+		method["outputs"] = formatTypeList(
 			externalFunctionType->returnParameterNames(),
-			externalFunctionType->returnParameterTypeNames(_contractDef.isLibrary())
+			externalFunctionType->returnParameterTypes(),
+			_contractDef.isLibrary()
 		);
 		abi.append(method);
 	}
@@ -69,9 +57,10 @@ Json::Value InterfaceHandler::abiInterface(ContractDefinition const& _contractDe
 		auto externalFunction = FunctionType(*_contractDef.constructor(), false).interfaceFunctionType();
 		solAssert(!!externalFunction, "");
 		method["payable"] = externalFunction->isPayable();
-		method["inputs"] = populateParameters(
+		method["inputs"] = formatTypeList(
 			externalFunction->parameterNames(),
-			externalFunction->parameterTypeNames(_contractDef.isLibrary())
+			externalFunction->parameterTypes(),
+			_contractDef.isLibrary()
 		);
 		abi.append(method);
 	}
@@ -179,6 +168,25 @@ Json::Value InterfaceHandler::devDocumentation(ContractDefinition const& _contra
 	return doc;
 }
 
+Json::Value InterfaceHandler::formatTypeList(
+	vector<string> const& _names,
+	vector<TypePointer> const& _types,
+	bool _forLibrary
+)
+{
+	Json::Value params(Json::arrayValue);
+	solAssert(_names.size() == _types.size(), "Names and types vector size does not match");
+	for (unsigned i = 0; i < _names.size(); ++i)
+	{
+		solAssert(_types[i], "");
+		Json::Value param;
+		param["name"] = _names[i];
+		param["type"] = _types[i]->canonicalName(_forLibrary);
+		params.append(param);
+	}
+	return params;
+}
+
 string InterfaceHandler::extractDoc(multimap<string, DocTag> const& _tags, string const& _name)
 {
 	string value;
diff --git a/libsolidity/interface/InterfaceHandler.h b/libsolidity/interface/InterfaceHandler.h
index b7e1bb003..56927d44e 100644
--- a/libsolidity/interface/InterfaceHandler.h
+++ b/libsolidity/interface/InterfaceHandler.h
@@ -37,6 +37,8 @@ namespace solidity
 
 // Forward declarations
 class ContractDefinition;
+class Type;
+using TypePointer = std::shared_ptr<Type const>;
 struct DocTag;
 enum class DocumentationType: uint8_t;
 
@@ -84,6 +86,14 @@ public:
 	static Json::Value devDocumentation(ContractDefinition const& _contractDef);
 
 private:
+	/// @returns a json value suitable for a list of types in function input or output
+	/// parameters or other places. If @a _forLibrary is true, complex types are referenced
+	/// by name, otherwise they are anonymously expanded.
+	static Json::Value formatTypeList(
+		std::vector<std::string> const& _names,
+		std::vector<TypePointer> const& _types,
+		bool _forLibrary
+	);
 	/// @returns concatenation of all content under the given tag name.
 	static std::string extractDoc(std::multimap<std::string, DocTag> const& _tags, std::string const& _name);
 };
diff --git a/test/libsolidity/SolidityNameAndTypeResolution.cpp b/test/libsolidity/SolidityNameAndTypeResolution.cpp
index b6067ea5c..472067ecd 100644
--- a/test/libsolidity/SolidityNameAndTypeResolution.cpp
+++ b/test/libsolidity/SolidityNameAndTypeResolution.cpp
@@ -1102,25 +1102,25 @@ BOOST_AUTO_TEST_CASE(state_variable_accessors)
 	BOOST_REQUIRE((contract = retrieveContract(source, 0)) != nullptr);
 	FunctionTypePointer function = retrieveFunctionBySignature(*contract, "foo()");
 	BOOST_REQUIRE(function && function->hasDeclaration());
-	auto returnParams = function->returnParameterTypeNames(false);
-	BOOST_CHECK_EQUAL(returnParams.at(0), "uint256");
+	auto returnParams = function->returnParameterTypes();
+	BOOST_CHECK_EQUAL(returnParams.at(0)->canonicalName(false), "uint256");
 	BOOST_CHECK(function->isConstant());
 
 	function = retrieveFunctionBySignature(*contract, "map(uint256)");
 	BOOST_REQUIRE(function && function->hasDeclaration());
-	auto params = function->parameterTypeNames(false);
-	BOOST_CHECK_EQUAL(params.at(0), "uint256");
-	returnParams = function->returnParameterTypeNames(false);
-	BOOST_CHECK_EQUAL(returnParams.at(0), "bytes4");
+	auto params = function->parameterTypes();
+	BOOST_CHECK_EQUAL(params.at(0)->canonicalName(false), "uint256");
+	returnParams = function->returnParameterTypes();
+	BOOST_CHECK_EQUAL(returnParams.at(0)->canonicalName(false), "bytes4");
 	BOOST_CHECK(function->isConstant());
 
 	function = retrieveFunctionBySignature(*contract, "multiple_map(uint256,uint256)");
 	BOOST_REQUIRE(function && function->hasDeclaration());
-	params = function->parameterTypeNames(false);
-	BOOST_CHECK_EQUAL(params.at(0), "uint256");
-	BOOST_CHECK_EQUAL(params.at(1), "uint256");
-	returnParams = function->returnParameterTypeNames(false);
-	BOOST_CHECK_EQUAL(returnParams.at(0), "bytes4");
+	params = function->parameterTypes();
+	BOOST_CHECK_EQUAL(params.at(0)->canonicalName(false), "uint256");
+	BOOST_CHECK_EQUAL(params.at(1)->canonicalName(false), "uint256");
+	returnParams = function->returnParameterTypes();
+	BOOST_CHECK_EQUAL(returnParams.at(0)->canonicalName(false), "bytes4");
 	BOOST_CHECK(function->isConstant());
 }