diff --git a/test/tools/ossfuzz/protoToYul.cpp b/test/tools/ossfuzz/protoToYul.cpp
index 95a42f49f..f79d1f4da 100644
--- a/test/tools/ossfuzz/protoToYul.cpp
+++ b/test/tools/ossfuzz/protoToYul.cpp
@@ -93,16 +93,18 @@ string ProtoConverter::visit(Literal const& _x)
 void ProtoConverter::consolidateVarDeclsInFunctionDef()
 {
 	m_currentFuncVars.clear();
-	auto &scopes = m_funcVars.back();
-	for (auto &s: scopes)
-		m_currentFuncVars.insert(m_currentFuncVars.end(), s.begin(), s.end());
+	auto const& scopes = m_funcVars.back();
+	for (auto const& s: scopes)
+		for (auto const& var: s)
+			m_currentFuncVars.push_back(&var);
 }
 
 void ProtoConverter::consolidateGlobalVarDecls()
 {
-	m_globalVars.clear();
-	for (auto &scope: m_variables)
-		m_globalVars.insert(m_globalVars.end(), scope.begin(), scope.end());
+	m_currentGlobalVars.clear();
+	for (auto const& scope: m_globalVars)
+		for (auto const& var: scope)
+			m_currentGlobalVars.push_back(&var);
 }
 
 bool ProtoConverter::varDeclAvailable()
@@ -115,7 +117,7 @@ bool ProtoConverter::varDeclAvailable()
 	else
 	{
 		consolidateGlobalVarDecls();
-		return m_globalVars.size() > 0;
+		return m_currentGlobalVars.size() > 0;
 	}
 }
 
@@ -131,13 +133,13 @@ void ProtoConverter::visit(VarRef const& _x)
 	{
 		// Ensure that there is at least one variable declaration to reference in function scope.
 		yulAssert(m_currentFuncVars.size() > 0, "Proto fuzzer: No variables to reference.");
-		m_output << m_currentFuncVars[_x.varnum() % m_currentFuncVars.size()];
+		m_output << *m_currentFuncVars[_x.varnum() % m_currentFuncVars.size()];
 	}
 	else
 	{
 		// Ensure that there is at least one variable declaration to reference in nested scopes.
-		yulAssert(m_globalVars.size() > 0, "Proto fuzzer: No global variables to reference.");
-		m_output << m_globalVars[_x.varnum() % m_globalVars.size()];
+		yulAssert(m_currentGlobalVars.size() > 0, "Proto fuzzer: No global variables to reference.");
+		m_output << *m_currentGlobalVars[_x.varnum() % m_currentGlobalVars.size()];
 	}
 }
 
@@ -282,7 +284,7 @@ void ProtoConverter::visit(VarDecl const& _x)
 	if (m_inFunctionDef)
 		m_funcVars.back().back().push_back(varName);
 	else
-		m_variables.back().push_back(varName);
+		m_globalVars.back().push_back(varName);
 }
 
 void ProtoConverter::visit(TypedVarDecl const& _x)
@@ -350,7 +352,7 @@ void ProtoConverter::visit(TypedVarDecl const& _x)
 	if (m_inFunctionDef)
 		m_funcVars.back().back().push_back(varName);
 	else
-		m_variables.back().push_back(varName);
+		m_globalVars.back().push_back(varName);
 }
 
 void ProtoConverter::visit(UnaryOp const& _x)
@@ -1134,7 +1136,7 @@ void ProtoConverter::openBlockScope()
 	if (m_inFunctionDef)
 		m_funcVars.back().push_back(vector<string>{});
 	else
-		m_variables.push_back(vector<string>{});
+		m_globalVars.push_back(vector<string>{});
 }
 
 void ProtoConverter::openFunctionScope(vector<string> const& _funcParams)
@@ -1173,8 +1175,8 @@ void ProtoConverter::closeBlockScope()
 		m_scopeFuncs.pop_back();
 	if (!m_inFunctionDef)
 	{
-		if (!m_variables.empty())
-			m_variables.pop_back();
+		if (!m_globalVars.empty())
+			m_globalVars.pop_back();
 	}
 	else
 	{
@@ -1197,7 +1199,7 @@ void ProtoConverter::addVarsToScope(vector<string> const& _vars)
 	if (m_inFunctionDef)
 		m_funcVars.back().back().insert(m_funcVars.back().back().end(), _vars.begin(), _vars.end());
 	else
-		m_variables.back().insert(m_variables.back().end(), _vars.begin(), _vars.end());
+		m_globalVars.back().insert(m_globalVars.back().end(), _vars.begin(), _vars.end());
 }
 
 void ProtoConverter::visit(Block const& _x)
diff --git a/test/tools/ossfuzz/protoToYul.h b/test/tools/ossfuzz/protoToYul.h
index 6823a2925..a0a7240ab 100644
--- a/test/tools/ossfuzz/protoToYul.h
+++ b/test/tools/ossfuzz/protoToYul.h
@@ -43,7 +43,7 @@ public:
 	ProtoConverter()
 	{
 		m_funcVars = std::vector<std::vector<std::vector<std::string>>>{};
-		m_variables = std::vector<std::vector<std::string>>{};
+		m_globalVars = std::vector<std::vector<std::string>>{};
 		m_inForBodyScope = false;
 		m_inForInitScope = false;
 		m_numNestedForLoops = 0;
@@ -312,13 +312,13 @@ private:
 	/// Variables in all function definitions
 	std::vector<std::vector<std::vector<std::string>>> m_funcVars;
 	/// Variables in current function definition
-	std::vector<std::string> m_currentFuncVars;
+	std::vector<std::string const*> m_currentFuncVars;
 	/// Variables in global scope
-	std::vector<std::string> m_globalVars;
+	std::vector<std::string const*> m_currentGlobalVars;
 	/// Functions in current scope
 	std::vector<std::vector<std::string>> m_scopeFuncs;
 	/// Variables
-	std::vector<std::vector<std::string>> m_variables;
+	std::vector<std::vector<std::string>> m_globalVars;
 	/// Functions
 	std::vector<std::string> m_functions;
 	/// Maps FunctionDef object to its name
diff --git a/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp b/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
index 155973e1f..689085240 100644
--- a/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
+++ b/test/tools/ossfuzz/yulProto_diff_ossfuzz.cpp
@@ -69,24 +69,17 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 
 	// AssemblyStack entry point
 	AssemblyStack stack(
-		langutil::EVMVersion(langutil::EVMVersion::istanbul()),
+		langutil::EVMVersion::istanbul(),
 		AssemblyStack::Language::StrictAssembly,
 		dev::solidity::OptimiserSettings::full()
 	);
 
-	try
+	// Parse protobuf mutated YUL code
+	if (!stack.parseAndAnalyze("source", yul_source) || !stack.parserResult()->code ||
+		!stack.parserResult()->analysisInfo)
 	{
-		// Parse protobuf mutated YUL code
-		if (!stack.parseAndAnalyze("source", yul_source) || !stack.parserResult()->code ||
-			!stack.parserResult()->analysisInfo)
-		{
-			printErrors(std::cout, stack.errors());
-			yulAssert(false, "Proto fuzzer generated malformed program");
-		}
-	}
-	catch (Exception const&)
-	{
-		return;
+		printErrors(std::cout, stack.errors());
+		yulAssert(false, "Proto fuzzer generated malformed program");
 	}
 
 	ostringstream os1;
@@ -94,7 +87,7 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 	yulFuzzerUtil::TerminationReason termReason = yulFuzzerUtil::interpret(
 		os1,
 		stack.parserResult()->code,
-		EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion(langutil::EVMVersion::istanbul()))
+		EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion::istanbul())
 	);
 
 	if (termReason == yulFuzzerUtil::TerminationReason::StepLimitReached)
@@ -104,7 +97,7 @@ DEFINE_PROTO_FUZZER(Program const& _input)
 	termReason = yulFuzzerUtil::interpret(
 		os2,
 		stack.parserResult()->code,
-		EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion(langutil::EVMVersion::istanbul())),
+		EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion::istanbul()),
 		(yul::test::yul_fuzzer::yulFuzzerUtil::maxSteps * 4)
 	);