diff --git a/neo-cli/CLI/MainService.Tools.cs b/neo-cli/CLI/MainService.Tools.cs
index 0686ddb8d..6c8f27cc7 100644
--- a/neo-cli/CLI/MainService.Tools.cs
+++ b/neo-cli/CLI/MainService.Tools.cs
@@ -5,7 +5,6 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Numerics;
-using System.Text;
 
 namespace Neo.CLI
 {
@@ -70,7 +69,7 @@ private string HexToString(string hexString)
             {
                 var clearHexString = ClearHexString(hexString);
                 var bytes = clearHexString.HexToBytes();
-                var utf8String = Encoding.UTF8.GetString(bytes);
+                var utf8String = Utility.StrictUTF8.GetString(bytes);
 
                 if (!IsPrintable(utf8String))
                 {
@@ -170,7 +169,7 @@ private string StringToHex(string strParam)
         {
             try
             {
-                var bytesParam = Encoding.UTF8.GetBytes(strParam);
+                var bytesParam = Utility.StrictUTF8.GetBytes(strParam);
                 return bytesParam.ToHexString();
             }
             catch
@@ -196,7 +195,7 @@ private string StringToBase64(string strParam)
         {
             try
             {
-                byte[] bytearray = Encoding.UTF8.GetBytes(strParam);
+                byte[] bytearray = Utility.StrictUTF8.GetBytes(strParam);
                 string base64 = Convert.ToBase64String(bytearray.AsSpan());
                 return base64;
             }
@@ -407,7 +406,7 @@ private string Base64ToString(string bytearray)
             try
             {
                 byte[] result = Convert.FromBase64String(bytearray);
-                string utf8string = Encoding.UTF8.GetString(result);
+                string utf8string = Utility.StrictUTF8.GetString(result);
 
                 if (!IsPrintable(utf8string))
                 {
diff --git a/neo-cli/CLI/MainService.cs b/neo-cli/CLI/MainService.cs
index 2dc8de110..176151f57 100644
--- a/neo-cli/CLI/MainService.cs
+++ b/neo-cli/CLI/MainService.cs
@@ -24,7 +24,6 @@
 using System.Linq;
 using System.Net;
 using System.Reflection;
-using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
 
@@ -263,7 +262,7 @@ private byte[] LoadDeploymentScript(string nefFilePath, string manifestFilePath,
             }
 
             NefFile file;
-            using (var stream = new BinaryReader(File.OpenRead(nefFilePath), Encoding.UTF8, false))
+            using (var stream = new BinaryReader(File.OpenRead(nefFilePath), Utility.StrictUTF8, false))
             {
                 file = stream.ReadSerializable<NefFile>();
             }