diff --git a/PSDify.psd1 b/PSDify.psd1
index 7bfb1fc..f6f8e02 100644
--- a/PSDify.psd1
+++ b/PSDify.psd1
@@ -1,6 +1,6 @@
 @{
     RootModule           = 'PSDify.psm1'
-    ModuleVersion        = '0.3.0'
+    ModuleVersion        = '0.3.1'
     CompatiblePSEditions = @('Core', 'Desktop')
     GUID                 = 'b791c4c0-ed46-4561-8713-5d4242e6bac7'
     Author               = 'kurokobo'
diff --git a/Public/Import-DifyApp.ps1 b/Public/Import-DifyApp.ps1
index 6401cb4..88f77c5 100644
--- a/Public/Import-DifyApp.ps1
+++ b/Public/Import-DifyApp.ps1
@@ -51,9 +51,9 @@ function Import-DifyApp {
             if ([System.Version]$SimplifiedVersion -lt [System.Version]"0.12.0") {
                 $Endpoint = Join-Url -Segments @($env:PSDIFY_URL, "/console/api/apps/import")
                 $Method = "POST"
-                $Body = $UTF8NoBOM.GetBytes((@{
-                            "data" = $RawContent
-                        } | ConvertTo-Json))
+                $Body = @{
+                    "data" = $RawContent
+                } | ConvertTo-Json
                 try {
                     $Response = Invoke-DifyRestMethod -Uri $Endpoint -Method $Method -Body $Body -Token $env:PSDIFY_CONSOLE_TOKEN
                 }
@@ -85,10 +85,10 @@ function Import-DifyApp {
             else {
                 $Endpoint = Join-Url -Segments @($env:PSDIFY_URL, "/console/api/apps/imports")
                 $Method = "POST"
-                $Body = $UTF8NoBOM.GetBytes((@{
-                            "mode"         = "yaml-content"
-                            "yaml_content" = $RawContent
-                        } | ConvertTo-Json))
+                $Body = @{
+                    "mode"         = "yaml-content"
+                    "yaml_content" = $RawContent
+                } | ConvertTo-Json
                 try {
                     $Response = Invoke-DifyRestMethod -Uri $Endpoint -Method $Method -Body $Body -Token $env:PSDIFY_CONSOLE_TOKEN
                 }
diff --git a/Public/Invoke-DifyRestMethod.ps1 b/Public/Invoke-DifyRestMethod.ps1
index c870052..46b872e 100644
--- a/Public/Invoke-DifyRestMethod.ps1
+++ b/Public/Invoke-DifyRestMethod.ps1
@@ -4,7 +4,7 @@ function Invoke-DifyRestMethod {
         [String] $Uri,
         [String] $Method = "GET",
         [String] $ContentType = "application/json",
-        [Object] $Body = $null,
+        [String] $Body = $null,
         [Hashtable] $Query = $null,
         [String] $Token = $null,
         [Microsoft.PowerShell.Commands.WebRequestSession] $Session = $null,
@@ -37,7 +37,8 @@ function Invoke-DifyRestMethod {
     }
     if (@("POST", "PUT", "PATCH", "DELETE") -contains $Method) {
         if ($Body) {
-            $RestMethodParams.Body = $Body
+            $UTF8NoBOM = New-Object "System.Text.UTF8Encoding" -ArgumentList @($false)
+            $RestMethodParams.Body = $UTF8NoBOM.GetBytes($Body)
         }
         if ($InFile) {
             $RestMethodParams.InFile = $InFile
diff --git a/Tests/Integration/52_Send-DifyChatMessage.Tests.ps1 b/Tests/Integration/52_Send-DifyChatMessage.Tests.ps1
index 8565821..54a70ab 100644
--- a/Tests/Integration/52_Send-DifyChatMessage.Tests.ps1
+++ b/Tests/Integration/52_Send-DifyChatMessage.Tests.ps1
@@ -1,4 +1,4 @@
-#Requires -Modules @{ ModuleName="Pester"; ModuleVersion="5.6" }
+#Requires -Modules @{ ModuleName="Pester"; ModuleVersion="5.6" }
 
 BeforeDiscovery {
     $PesterPhase = "BeforeDiscovery"
@@ -61,6 +61,12 @@ Describe "Send-DifyChatMessage" -Tag "chat" {
 
             Assert-MockCalled -ModuleName PSDify -CommandName Write-Host -ParameterFilter { $Object -like "*Pong*" }
         }
+        It "should send messages without knowledge with multibyte characters" {
+            $env:PSDIFY_APP_TOKEN = $TestAppWithoutKnowledgeAPIKey.Token
+            Send-DifyChatMessage -NewSession -Message "日本語で朝の挨拶は？ ひらがなで。"
+
+            Assert-MockCalled -ModuleName PSDify -CommandName Write-Host -ParameterFilter { $Object -like "*おはよ*" }
+        }
         It "should send messages with knowledge" {
             $env:PSDIFY_APP_TOKEN = $TestAppWithKnowledgeAPIKey.Token
             Send-DifyChatMessage -NewSession -Message "What is the vegetable that is deep ruby red in color ?"