diff --git a/libyul/backends/evm/ConstantOptimiser.h b/libyul/backends/evm/ConstantOptimiser.h
index 52d78be86..e95a152c8 100644
--- a/libyul/backends/evm/ConstantOptimiser.h
+++ b/libyul/backends/evm/ConstantOptimiser.h
@@ -58,7 +58,7 @@ public:
 	struct Representation
 	{
 		std::unique_ptr<Expression> expression;
-		size_t cost = size_t(-1);
+		bigint cost;
 	};
 
 private:
diff --git a/libyul/backends/evm/EVMMetrics.cpp b/libyul/backends/evm/EVMMetrics.cpp
index de28792d3..dfb716c19 100644
--- a/libyul/backends/evm/EVMMetrics.cpp
+++ b/libyul/backends/evm/EVMMetrics.cpp
@@ -37,23 +37,23 @@ using namespace solidity;
 using namespace solidity::yul;
 using namespace solidity::util;
 
-size_t GasMeter::costs(Expression const& _expression) const
+bigint GasMeter::costs(Expression const& _expression) const
 {
 	return combineCosts(GasMeterVisitor::costs(_expression, m_dialect, m_isCreation));
 }
 
-size_t GasMeter::instructionCosts(evmasm::Instruction _instruction) const
+bigint GasMeter::instructionCosts(evmasm::Instruction _instruction) const
 {
 	return combineCosts(GasMeterVisitor::instructionCosts(_instruction, m_dialect, m_isCreation));
 }
 
-size_t GasMeter::combineCosts(std::pair<size_t, size_t> _costs) const
+bigint GasMeter::combineCosts(std::pair<bigint, bigint> _costs) const
 {
 	return _costs.first * m_runs + _costs.second;
 }
 
 
-pair<size_t, size_t> GasMeterVisitor::costs(
+pair<bigint, bigint> GasMeterVisitor::costs(
 	Expression const& _expression,
 	EVMDialect const& _dialect,
 	bool _isCreation
@@ -64,7 +64,7 @@ pair<size_t, size_t> GasMeterVisitor::costs(
 	return {gmv.m_runGas, gmv.m_dataGas};
 }
 
-pair<size_t, size_t> GasMeterVisitor::instructionCosts(
+pair<bigint, bigint> GasMeterVisitor::instructionCosts(
 	evmasm::Instruction _instruction,
 	EVMDialect const& _dialect,
 	bool _isCreation
@@ -92,11 +92,11 @@ void GasMeterVisitor::operator()(Literal const& _lit)
 	m_runGas += evmasm::GasMeter::runGas(evmasm::Instruction::PUSH1);
 	m_dataGas +=
 		singleByteDataGas() +
-		static_cast<size_t>(evmasm::GasMeter::dataGas(
+		evmasm::GasMeter::dataGas(
 			toCompactBigEndian(valueOfLiteral(_lit), 1),
 			m_isCreation,
 			m_dialect.evmVersion()
-		));
+		);
 }
 
 void GasMeterVisitor::operator()(Identifier const&)
@@ -105,7 +105,7 @@ void GasMeterVisitor::operator()(Identifier const&)
 	m_dataGas += singleByteDataGas();
 }
 
-size_t GasMeterVisitor::singleByteDataGas() const
+bigint GasMeterVisitor::singleByteDataGas() const
 {
 	if (m_isCreation)
 		return evmasm::GasCosts::txDataNonZeroGas(m_dialect.evmVersion());
diff --git a/libyul/backends/evm/EVMMetrics.h b/libyul/backends/evm/EVMMetrics.h
index ec59976f7..19702b8f3 100644
--- a/libyul/backends/evm/EVMMetrics.h
+++ b/libyul/backends/evm/EVMMetrics.h
@@ -42,36 +42,36 @@ struct EVMDialect;
 class GasMeter
 {
 public:
-	GasMeter(EVMDialect const& _dialect, bool _isCreation, size_t _runs):
+	GasMeter(EVMDialect const& _dialect, bool _isCreation, bigint _runs):
 		m_dialect(_dialect),
 		m_isCreation{_isCreation},
 		m_runs(_isCreation? 1 : _runs)
 	{}
 
 	/// @returns the full combined costs of deploying and evaluating the expression.
-	size_t costs(Expression const& _expression) const;
+	bigint costs(Expression const& _expression) const;
 	/// @returns the combined costs of deploying and running the instruction, not including
 	/// the costs for its arguments.
-	size_t instructionCosts(evmasm::Instruction _instruction) const;
+	bigint instructionCosts(evmasm::Instruction _instruction) const;
 
 private:
-	size_t combineCosts(std::pair<size_t, size_t> _costs) const;
+	bigint combineCosts(std::pair<bigint, bigint> _costs) const;
 
 	EVMDialect const& m_dialect;
 	bool m_isCreation = false;
-	size_t m_runs;
+	bigint m_runs;
 };
 
 class GasMeterVisitor: public ASTWalker
 {
 public:
-	static std::pair<size_t, size_t> costs(
+	static std::pair<bigint, bigint> costs(
 		Expression const& _expression,
 		EVMDialect const& _dialect,
 		bool _isCreation
 	);
 
-	static std::pair<size_t, size_t> instructionCosts(
+	static std::pair<bigint, bigint> instructionCosts(
 		evmasm::Instruction _instruction,
 		EVMDialect const& _dialect,
 		bool _isCreation = false
@@ -88,7 +88,7 @@ public:
 	void operator()(Identifier const& _identifier) override;
 
 private:
-	size_t singleByteDataGas() const;
+	bigint singleByteDataGas() const;
 	/// Computes the cost of storing and executing the single instruction (excluding its arguments).
 	/// For EXP, it assumes that the exponent is at most 255.
 	/// Does not work particularly exact for anything apart from arithmetic.
@@ -96,8 +96,8 @@ private:
 
 	EVMDialect const& m_dialect;
 	bool m_isCreation = false;
-	size_t m_runGas = 0;
-	size_t m_dataGas = 0;
+	bigint m_runGas = 0;
+	bigint m_dataGas = 0;
 };
 
 }