diff --git a/ExpressionCompiler.cpp b/ExpressionCompiler.cpp
index 5667098db..33c10aa36 100644
--- a/ExpressionCompiler.cpp
+++ b/ExpressionCompiler.cpp
@@ -194,13 +194,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 		solAssert(_functionCall.getArguments().size() == 1, "");
 		Expression const& firstArgument = *_functionCall.getArguments().front();
 		firstArgument.accept(*this);
-		if (firstArgument.getType()->getCategory() == Type::Category::CONTRACT &&
-				_functionCall.getType()->getCategory() == Type::Category::INTEGER)
-		{
-			// explicit type conversion contract -> address, nothing to do.
-		}
-		else
-			appendTypeConversion(*firstArgument.getType(), *_functionCall.getType());
+		appendTypeConversion(*firstArgument.getType(), *_functionCall.getType());
 	}
 	else
 	{
@@ -250,13 +244,17 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 			FunctionCallOptions options;
 			options.bare = true;
 			options.obtainAddress = [&]() { _functionCall.getExpression().accept(*this); };
-			options.obtainValue = [&]() { arguments.front()->accept(*this); };
+			options.obtainValue = [&]()
+			{
+				arguments.front()->accept(*this);
+				appendTypeConversion(*arguments.front()->getType(),
+									 *function.getParameterTypes().front(), true);
+			};
 			appendExternalFunctionCall(FunctionType({}, {}, Location::EXTERNAL), {}, options);
 			break;
 		}
 		case Location::SUICIDE:
 			arguments.front()->accept(*this);
-			//@todo might not be necessary
 			appendTypeConversion(*arguments.front()->getType(), *function.getParameterTypes().front(), true);
 			m_context << eth::Instruction::SUICIDE;
 			break;
@@ -362,6 +360,8 @@ void ExpressionCompiler::endVisit(MemberAccess const& _memberAccess)
 		break;
 	case Type::Category::CONTRACT:
 	{
+		appendTypeConversion(*_memberAccess.getExpression().getType(),
+							 IntegerType(0, IntegerType::Modifier::ADDRESS), true);
 		ContractType const& type = dynamic_cast<ContractType const&>(*_memberAccess.getExpression().getType());
 		m_context << type.getFunctionIdentifier(member);
 		break;
@@ -592,15 +592,36 @@ void ExpressionCompiler::appendTypeConversion(Type const& _typeOnStack, Type con
 		return;
 	Type::Category stackTypeCategory = _typeOnStack.getCategory();
 	Type::Category targetTypeCategory = _targetType.getCategory();
-	if (stackTypeCategory == Type::Category::INTEGER)
+	if (stackTypeCategory == Type::Category::INTEGER || stackTypeCategory == Type::Category::CONTRACT ||
+			 stackTypeCategory == Type::Category::INTEGER_CONSTANT)
 	{
 		solAssert(targetTypeCategory == Type::Category::INTEGER || targetTypeCategory == Type::Category::CONTRACT, "");
-		appendHighBitsCleanup(dynamic_cast<IntegerType const&>(_typeOnStack));
+		IntegerType addressType(0, IntegerType::Modifier::ADDRESS);
+		IntegerType const& targetType = targetTypeCategory == Type::Category::INTEGER
+			? dynamic_cast<IntegerType const&>(_targetType) : addressType;
+		if (stackTypeCategory == Type::Category::INTEGER_CONSTANT)
+		{
+			IntegerConstantType const& constType = dynamic_cast<IntegerConstantType const&>(_typeOnStack);
+			// We know that the stack is clean, we only have to clean for a narrowing conversion
+			// where cleanup is forced.
+			if (targetType.getNumBits() < constType.getIntegerType()->getNumBits() && _cleanupNeeded)
+				appendHighBitsCleanup(targetType);
+		}
+		else
+		{
+			IntegerType const& typeOnStack = stackTypeCategory == Type::Category::INTEGER
+				? dynamic_cast<IntegerType const&>(_typeOnStack) : addressType;
+			// Widening: clean up according to source type width
+			// Non-widening and force: clean up according to target type bits
+			if (targetType.getNumBits() > typeOnStack.getNumBits())
+				appendHighBitsCleanup(typeOnStack);
+			else if (_cleanupNeeded)
+				appendHighBitsCleanup(targetType);
+		}
 	}
-	else if (stackTypeCategory == Type::Category::INTEGER_CONSTANT)
-		solAssert(targetTypeCategory == Type::Category::INTEGER || targetTypeCategory == Type::Category::CONTRACT, "");
 	else if (stackTypeCategory == Type::Category::STRING)
 	{
+		solAssert(targetTypeCategory == Type::Category::STRING, "");
 		// nothing to do, strings are high-order-bit-aligned
 		//@todo clear lower-order bytes if we allow explicit conversion to shorter strings
 	}