diff --git a/CompilerContext.h b/CompilerContext.h
index 87f90d4c4..e752d59b8 100644
--- a/CompilerContext.h
+++ b/CompilerContext.h
@@ -83,6 +83,7 @@ public:
 	/// Converts an offset relative to the current stack height to a value that can be used later
 	/// with baseToCurrentStackOffset to point to the same stack element.
 	unsigned currentToBaseStackOffset(unsigned _offset) const;
+	/// @returns pair of slot and byte offset of the value inside this slot.
 	std::pair<u256, unsigned> getStorageLocationOfVariable(Declaration const& _declaration) const;
 
 	/// Appends a JUMPI instruction to a new tag and @returns the tag
diff --git a/ExpressionCompiler.cpp b/ExpressionCompiler.cpp
index 59781f821..30cc3c6f8 100644
--- a/ExpressionCompiler.cpp
+++ b/ExpressionCompiler.cpp
@@ -62,8 +62,19 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 
 	unsigned length = 0;
 	TypePointers const& paramTypes = accessorType.getParameterTypes();
-	// move arguments to memory
-	for (TypePointer const& paramType: boost::adaptors::reverse(paramTypes))
+
+	// to exclude the last key if it is an array
+	TypePointer finalMappingValueType = _varDecl.getType();
+	while (finalMappingValueType->getCategory() == Type::Category::Mapping)
+		finalMappingValueType = dynamic_cast<MappingType const&>(*finalMappingValueType).getValueType();
+
+	bool finalIsArrayType = finalMappingValueType->getCategory() == Type::Category::Array;
+	TypePointers mappingKeys(paramTypes);
+	if (finalIsArrayType)
+		mappingKeys.pop_back();
+
+	// move mapping arguments to memory
+	for (TypePointer const& paramType: boost::adaptors::reverse(mappingKeys))
 		length += CompilerUtils(m_context).storeInMemory(length, *paramType, true);
 
 	// retrieve the position of the variable
@@ -71,20 +82,21 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 	m_context << location.first;
 
 	TypePointer returnType = _varDecl.getType();
-	if (ArrayType const* arrayType = dynamic_cast<ArrayType const*>(returnType.get()))
-	{
-		(void)arrayType;
-	} else
-		for (TypePointer const& paramType: paramTypes)
-		{
-			// move offset to memory
-			CompilerUtils(m_context).storeInMemory(length);
-			unsigned argLen = paramType->getCalldataEncodedSize();
-			length -= argLen;
-			m_context << u256(argLen + 32) << u256(length) << eth::Instruction::SHA3;
 
-			returnType = dynamic_cast<MappingType const&>(*returnType).getValueType();
-		}
+	for (TypePointer const& paramType: mappingKeys)
+	{
+		// move offset to memory
+		CompilerUtils(m_context).storeInMemory(length);
+		unsigned argLen = paramType->getCalldataEncodedSize();
+		length -= argLen;
+		m_context << u256(argLen + 32) << u256(length) << eth::Instruction::SHA3;
+
+		returnType = dynamic_cast<MappingType const&>(*returnType).getValueType();
+	}
+	if (finalMappingValueType->isDynamicallySized())
+	{
+
+	}
 
 	unsigned retSizeOnStack = 0;
 	solAssert(accessorType.getReturnParameterTypes().size() >= 1, "");
@@ -100,7 +112,7 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 			pair<u256, unsigned> const& offsets = structType->getStorageOffsetsOfMember(names[i]);
 			m_context << eth::Instruction::DUP1 << u256(offsets.first) << eth::Instruction::ADD << u256(offsets.second);
 			StorageItem(m_context, *types[i]).retrieveValue(SourceLocation(), true);
-			solAssert(types[i]->getSizeOnStack() == 1, "Returning struct elements with stack size != 1 not yet implemented.");
+			solAssert(types[i]->getSizeOnStack() == 1, "Returning struct elements with stack size != 1 is not yet implemented.");
 			m_context << eth::Instruction::SWAP1;
 			retSizeOnStack += types[i]->getSizeOnStack();
 		}
@@ -114,7 +126,7 @@ void ExpressionCompiler::appendStateVariableAccessor(VariableDeclaration const&
 		StorageItem(m_context, *returnType).retrieveValue(SourceLocation(), true);
 		retSizeOnStack = returnType->getSizeOnStack();
 	}
-	solAssert(retSizeOnStack <= 15, "Stack too deep.");
+	solAssert(retSizeOnStack <= 15, "Stack is too deep.");
 	m_context << eth::dupInstruction(retSizeOnStack + 1);
 	m_context.appendJump(eth::AssemblyItem::JumpType::OutOfFunction);
 }
@@ -753,7 +765,7 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
 		appendTypeMoveToMemory(IntegerType(256));
 		m_context << u256(0) << eth::Instruction::SHA3;
 		m_context << u256(0);
-		setLValueToStorageItem( _indexAccess);
+		setLValueToStorageItem(_indexAccess);
 	}
 	else if (baseType.getCategory() == Type::Category::Array)
 	{
diff --git a/Types.cpp b/Types.cpp
index 0c80a0f7d..9a5b120b6 100644
--- a/Types.cpp
+++ b/Types.cpp
@@ -1002,17 +1002,17 @@ FunctionType::FunctionType(VariableDeclaration const& _varDecl):
 				retParamNames.push_back(member.first);
 				retParams.push_back(member.second);
 			}
-	} else
-		if (auto arrayType = dynamic_cast<ArrayType const*>(returnType.get()))
-		{
-			params.push_back(make_shared<IntegerType>(256));
-			paramNames.push_back("");
-			returnType = arrayType->getBaseType();
-		} else
-		{
-			retParams.push_back(returnType);
-			retParamNames.push_back("");
-		}
+	} else if (auto arrayType = dynamic_cast<ArrayType const*>(returnType.get()))
+	{
+		params.push_back(make_shared<IntegerType>(256));
+		paramNames.push_back("");
+		returnType = arrayType->getBaseType();
+	}
+	else
+	{
+		retParams.push_back(returnType);
+		retParamNames.push_back("");
+	}
 
 	swap(params, m_parameterTypes);
 	swap(paramNames, m_parameterNames);