diff --git a/core/vm/opcodes.go b/core/vm/opcodes.go
index 0820b20fb1..47e0211b70 100644
--- a/core/vm/opcodes.go
+++ b/core/vm/opcodes.go
@@ -634,3 +634,11 @@ var stringToOp = map[string]OpCode{
 func StringToOp(str string) OpCode {
 	return stringToOp[str]
 }
+
+// IsCancunOpcode specifies if an opcode is added at Cancun fork.
+func (op OpCode) IsCancunOpcode() bool {
+	if op == BLOBHASH || op == BLOBBASEFEE || op == TLOAD || op == TSTORE || op == MCOPY {
+		return true
+	}
+	return false
+}
diff --git a/core/vm/runtime/runtime_test.go b/core/vm/runtime/runtime_test.go
index e7c69fdeee..59ff28742c 100644
--- a/core/vm/runtime/runtime_test.go
+++ b/core/vm/runtime/runtime_test.go
@@ -682,7 +682,12 @@ func TestColdAccountAccessCost(t *testing.T) {
 				Tracer: &tracing.Hooks{
 					OnOpcode: func(pc uint64, op byte, gas, cost uint64, scope tracing.OpContext, rData []byte, depth int, isCancun bool, err error) {
 						// Uncomment to investigate failures:
-						//t.Logf("%d: %v %d", step, vm.OpCode(op).String(), cost)
+						// opString := vm.OpCode(op).String()
+						// Use hex string if Cancun is inactive but the opcode is invalid before Cancun fork
+						// if !isCancun &&  vm.OpCode(op).IsCancunOpcode() {
+						// 	opString = fmt.Sprintf("0x%x", byte(vm.OpCode(op)))
+						// }
+						//t.Logf("%d: %v %d", step, opString, cost)
 						if step == tc.step {
 							have = cost
 						}
@@ -936,7 +941,12 @@ func TestDelegatedAccountAccessCost(t *testing.T) {
 				Tracer: &tracing.Hooks{
 					OnOpcode: func(pc uint64, op byte, gas, cost uint64, scope tracing.OpContext, rData []byte, depth int, isCancun bool, err error) {
 						// Uncomment to investigate failures:
-						t.Logf("%d: %v %d", step, vm.OpCode(op).String(), cost)
+						opString := vm.OpCode(op).String()
+						// Use hex string if Cancun is inactive but the opcode is invalid before Cancun fork
+						if !isCancun && vm.OpCode(op).IsCancunOpcode() {
+							opString = fmt.Sprintf("0x%x", byte(vm.OpCode(op)))
+						}
+						t.Logf("%d: %v %d", step, opString, cost)
 						if step == tc.step {
 							have = cost
 						}
diff --git a/eth/tracers/logger/logger.go b/eth/tracers/logger/logger.go
index 2bf7ac0694..b36029a85a 100644
--- a/eth/tracers/logger/logger.go
+++ b/eth/tracers/logger/logger.go
@@ -157,10 +157,15 @@ type structLogLegacy struct {
 }
 
 // toLegacyJSON converts the structLog to legacy json-encoded legacy form.
-func (s *StructLog) toLegacyJSON() json.RawMessage {
+func (s *StructLog) toLegacyJSON(isCancun bool) json.RawMessage {
+	opString := s.OpName()
+	// Use hex string if Cancun is inactive but the opcode is invalid before Cancun fork
+	if !isCancun && s.Op.IsCancunOpcode() {
+		opString = fmt.Sprintf("0x%x", byte(s.Op))
+	}
 	msg := structLogLegacy{
 		Pc:            s.Pc,
-		Op:            s.Op.String(),
+		Op:            opString,
 		Gas:           s.Gas,
 		GasCost:       s.GasCost,
 		Depth:         s.Depth,
@@ -315,7 +320,7 @@ func (l *StructLogger) OnOpcode(pc uint64, opcode byte, gas, cost uint64, scope
 
 	// create a log
 	if l.writer == nil {
-		entry := log.toLegacyJSON()
+		entry := log.toLegacyJSON(isCancun)
 		l.resultSize += len(entry)
 		l.logs = append(l.logs, entry)
 		return
@@ -496,7 +501,12 @@ func (t *mdLogger) OnOpcode(pc uint64, op byte, gas, cost uint64, scope tracing.
 		return
 	}
 	stack := scope.StackData()
-	fmt.Fprintf(t.out, "| %4d  | %10v  |  %3d |%10v |", pc, vm.OpCode(op).String(),
+	opString := vm.OpCode(op).String()
+	// Use hex string if Cancun is inactive but the opcode is invalid before Cancun fork
+	if !isCancun && vm.OpCode(op).IsCancunOpcode() {
+		opString = fmt.Sprintf("0x%x", byte(vm.OpCode(op)))
+	}
+	fmt.Fprintf(t.out, "| %4d  | %10v  |  %3d |%10v |", pc, opString,
 		cost, t.env.StateDB.GetRefund())
 
 	if !t.cfg.DisableStack {