diff --git a/pkg/vm/vm.go b/pkg/vm/vm.go
index 4b56d1f8f..ba11b3e80 100644
--- a/pkg/vm/vm.go
+++ b/pkg/vm/vm.go
@@ -615,15 +615,9 @@ func (v *VM) execute(ctx *Context, op opcode.Opcode, parameter []byte) (err erro
 			panic("negative index")
 		}
 		s := v.estack.Pop().Bytes()
-		if o > len(s) {
-			// panic("invalid offset")
-			// FIXME revert when NEO 3.0 https://github.com/nspcc-dev/neo-go/issues/477
-			v.estack.PushVal("")
-			break
-		}
 		last := l + o
 		if last > len(s) {
-			last = len(s)
+			panic("invalid offset")
 		}
 		v.estack.PushVal(s[o:last])
 
diff --git a/pkg/vm/vm_test.go b/pkg/vm/vm_test.go
index e1572e22e..7b911d5d8 100644
--- a/pkg/vm/vm_test.go
+++ b/pkg/vm/vm_test.go
@@ -2267,11 +2267,7 @@ func TestSUBSTRBadOffset(t *testing.T) {
 	vm.estack.PushVal(7)
 	vm.estack.PushVal(1)
 
-	// checkVMFailed(t, vm)
-	// FIXME revert when NEO 3.0 https://github.com/nspcc-dev/neo-go/issues/477
-	runVM(t, vm)
-	assert.Equal(t, 1, vm.estack.Len())
-	assert.Equal(t, []byte{}, vm.estack.Peek(0).Bytes())
+	checkVMFailed(t, vm)
 }
 
 func TestSUBSTRBigLen(t *testing.T) {
@@ -2280,9 +2276,7 @@ func TestSUBSTRBigLen(t *testing.T) {
 	vm.estack.PushVal([]byte("abcdef"))
 	vm.estack.PushVal(1)
 	vm.estack.PushVal(6)
-	runVM(t, vm)
-	assert.Equal(t, 1, vm.estack.Len())
-	assert.Equal(t, []byte("bcdef"), vm.estack.Pop().Bytes())
+	checkVMFailed(t, vm)
 }
 
 func TestSUBSTRBad387(t *testing.T) {
@@ -2293,9 +2287,7 @@ func TestSUBSTRBad387(t *testing.T) {
 	vm.estack.PushVal(b)
 	vm.estack.PushVal(1)
 	vm.estack.PushVal(6)
-	runVM(t, vm)
-	assert.Equal(t, 1, vm.estack.Len())
-	assert.Equal(t, []byte("bcdef"), vm.estack.Pop().Bytes())
+	checkVMFailed(t, vm)
 }
 
 func TestSUBSTRBadNegativeOffset(t *testing.T) {