diff --git a/libevmasm/EVMAssemblyStack.cpp b/libevmasm/EVMAssemblyStack.cpp
index ff1b7c11c..0348aff4d 100644
--- a/libevmasm/EVMAssemblyStack.cpp
+++ b/libevmasm/EVMAssemblyStack.cpp
@@ -48,12 +48,12 @@ void EVMAssemblyStack::assemble()
 	solAssert(!m_evmRuntimeAssembly);
 
 	m_object = m_evmAssembly->assemble();
-	m_sourceMapping.emplace(AssemblyItem::computeSourceMapping(m_evmAssembly->items(), sourceIndices()));
+	m_sourceMapping = AssemblyItem::computeSourceMapping(m_evmAssembly->items(), sourceIndices());
 	if (m_evmAssembly->numSubs() > 0)
 	{
 		m_evmRuntimeAssembly = make_shared<evmasm::Assembly>(m_evmAssembly->sub(0));
 		solAssert(m_evmRuntimeAssembly && !m_evmRuntimeAssembly->isCreation());
-		m_runtimeSourceMapping.emplace(AssemblyItem::computeSourceMapping(m_evmRuntimeAssembly->items(), sourceIndices()));
+		m_runtimeSourceMapping = AssemblyItem::computeSourceMapping(m_evmRuntimeAssembly->items(), sourceIndices());
 		m_runtimeObject = m_evmRuntimeAssembly->assemble();
 	}
 }
@@ -87,13 +87,13 @@ map<string, unsigned> EVMAssemblyStack::sourceIndices() const
 string const* EVMAssemblyStack::sourceMapping(string const& _contractName) const
 {
 	solAssert(_contractName == m_name);
-	return m_sourceMapping.has_value() ? &m_sourceMapping.value() : nullptr;
+	return &m_sourceMapping;
 }
 
 string const* EVMAssemblyStack::runtimeSourceMapping(string const& _contractName) const
 {
 	solAssert(_contractName == m_name);
-	return m_runtimeSourceMapping.has_value() ? &m_runtimeSourceMapping.value() : nullptr;
+	return &m_runtimeSourceMapping;
 }
 
 Json::Value EVMAssemblyStack::assemblyJSON(string const& _contractName) const
diff --git a/libevmasm/EVMAssemblyStack.h b/libevmasm/EVMAssemblyStack.h
index cc90486e7..3f5b5d178 100644
--- a/libevmasm/EVMAssemblyStack.h
+++ b/libevmasm/EVMAssemblyStack.h
@@ -79,8 +79,8 @@ private:
 	evmasm::LinkerObject m_runtimeObject; ///< Runtime object.
 	std::vector<std::string> m_sourceList;
 	langutil::DebugInfoSelection m_debugInfoSelection = langutil::DebugInfoSelection::Default();
-	std::optional<std::string const> m_sourceMapping;
-	std::optional<std::string const> m_runtimeSourceMapping;
+	std::string m_sourceMapping;
+	std::string m_runtimeSourceMapping;
 };
 
 } // namespace solidity::evmasm