diff --git a/core/vm/evm.go b/core/vm/evm.go
index b835d1886962..8b7a7cc95ddf 100644
--- a/core/vm/evm.go
+++ b/core/vm/evm.go
@@ -41,7 +41,7 @@ type (
 )
 
 // run runs the given contract and takes care of running precompiles with a fallback to the byte code interpreter.
-func run(evm *EVM, contract *Contract, input []byte) ([]byte, error) {
+func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, error) {
 	if contract.CodeAddr != nil {
 		precompiles := PrecompiledContractsHomestead
 		if evm.ChainConfig().IsByzantium(evm.BlockNumber) {
@@ -61,7 +61,7 @@ func run(evm *EVM, contract *Contract, input []byte) ([]byte, error) {
 				}(evm.interpreter)
 				evm.interpreter = interpreter
 			}
-			return interpreter.Run(contract, input)
+			return interpreter.Run(contract, input, readOnly)
 		}
 	}
 	return nil, ErrNoCompatibleInterpreter
@@ -217,7 +217,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 			evm.vmConfig.Tracer.CaptureEnd(ret, gas-contract.Gas, time.Since(start), err)
 		}()
 	}
-	ret, err = run(evm, contract, input)
+	ret, err = run(evm, contract, input, false)
 
 	// When an error was returned by the EVM or when setting the creation code
 	// above we revert to the snapshot and consume any gas remaining. Additionally
@@ -262,7 +262,7 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
 	contract := NewContract(caller, to, value, gas)
 	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
 
-	ret, err = run(evm, contract, input)
+	ret, err = run(evm, contract, input, false)
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
 		if err != errExecutionReverted {
@@ -295,7 +295,7 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
 	contract := NewContract(caller, to, nil, gas).AsDelegate()
 	contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
 
-	ret, err = run(evm, contract, input)
+	ret, err = run(evm, contract, input, false)
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
 		if err != errExecutionReverted {
@@ -317,13 +317,6 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 	if evm.depth > int(params.CallCreateDepth) {
 		return nil, gas, ErrDepth
 	}
-	// Make sure the readonly is only set if we aren't in readonly yet
-	// this makes also sure that the readonly flag isn't removed for
-	// child calls.
-	if !evm.interpreter.IsReadOnly() {
-		evm.interpreter.SetReadOnly(true)
-		defer func() { evm.interpreter.SetReadOnly(false) }()
-	}
 
 	var (
 		to       = AccountRef(addr)
@@ -338,7 +331,7 @@ func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte
 	// When an error was returned by the EVM or when setting the creation code
 	// above we revert to the snapshot and consume any gas remaining. Additionally
 	// when we're in Homestead this also counts for code storage gas errors.
-	ret, err = run(evm, contract, input)
+	ret, err = run(evm, contract, input, true)
 	if err != nil {
 		evm.StateDB.RevertToSnapshot(snapshot)
 		if err != errExecutionReverted {
@@ -391,7 +384,7 @@ func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.I
 	}
 	start := time.Now()
 
-	ret, err = run(evm, contract, nil)
+	ret, err = run(evm, contract, nil, false)
 
 	// check whether the max code size has been exceeded
 	maxCodeSizeExceeded := evm.ChainConfig().IsEIP158(evm.BlockNumber) && len(ret) > params.MaxCodeSize
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index 3e5503855804..35480b83d88e 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -53,7 +53,7 @@ type Config struct {
 type Interpreter interface {
 	// Run loops and evaluates the contract's code with the given input data and returns
 	// the return byte-slice and an error if one occurred.
-	Run(contract *Contract, input []byte) ([]byte, error)
+	Run(contract *Contract, input []byte, static bool) ([]byte, error)
 	// CanRun tells if the contract, passed as an argument, can be
 	// run by the current interpreter. This is meant so that the
 	// caller can do something like:
@@ -66,10 +66,6 @@ type Interpreter interface {
 	// }
 	// ```
 	CanRun([]byte) bool
-	// IsReadOnly reports if the interpreter is in read only mode.
-	IsReadOnly() bool
-	// SetReadOnly sets (or unsets) read only mode in the interpreter.
-	SetReadOnly(bool)
 }
 
 // EVMInterpreter represents an EVM interpreter
@@ -131,11 +127,26 @@ func (in *EVMInterpreter) enforceRestrictions(op OpCode, operation operation, st
 // It's important to note that any errors returned by the interpreter should be
 // considered a revert-and-consume-all-gas operation except for
 // errExecutionReverted which means revert-and-keep-gas-left.
-func (in *EVMInterpreter) Run(contract *Contract, input []byte) (ret []byte, err error) {
+func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (ret []byte, err error) {
+	if in.intPool == nil {
+		in.intPool = poolOfIntPools.get()
+		defer func() {
+			poolOfIntPools.put(in.intPool)
+			in.intPool = nil
+		}()
+	}
+
 	// Increment the call depth which is restricted to 1024
 	in.evm.depth++
 	defer func() { in.evm.depth-- }()
 
+	// Make sure the readOnly is only set if we aren't in readOnly yet.
+	// This makes also sure that the readOnly flag isn't removed for child calls.
+	if readOnly && !in.readOnly {
+		in.readOnly = true
+		defer func() { in.readOnly = false }()
+	}
+
 	// Reset the previous call's return data. It's unimportant to preserve the old buffer
 	// as every returning call will return new data anyway.
 	in.returnData = nil
@@ -258,13 +269,3 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte) (ret []byte, err
 func (in *EVMInterpreter) CanRun(code []byte) bool {
 	return true
 }
-
-// IsReadOnly reports if the interpreter is in read only mode.
-func (in *EVMInterpreter) IsReadOnly() bool {
-	return in.readOnly
-}
-
-// SetReadOnly sets (or unsets) read only mode in the interpreter.
-func (in *EVMInterpreter) SetReadOnly(ro bool) {
-	in.readOnly = ro
-}
\ No newline at end of file
diff --git a/eth/tracers/tracer_test.go b/eth/tracers/tracer_test.go
index 117c376b8165..58b62472451c 100644
--- a/eth/tracers/tracer_test.go
+++ b/eth/tracers/tracer_test.go
@@ -49,7 +49,7 @@ func runTrace(tracer *Tracer) (json.RawMessage, error) {
 	contract := vm.NewContract(account{}, account{}, big.NewInt(0), 10000)
 	contract.Code = []byte{byte(vm.PUSH1), 0x1, byte(vm.PUSH1), 0x1, 0x0}
 
-	_, err := env.Interpreter().Run(contract, []byte{})
+	_, err := env.Interpreter().Run(contract, []byte{}, false)
 	if err != nil {
 		return nil, err
 	}