diff --git a/src/clients/channel-access-token/lib/Configuration.php b/src/clients/channel-access-token/lib/Configuration.php
index 7ca1f990..9829fc59 100644
--- a/src/clients/channel-access-token/lib/Configuration.php
+++ b/src/clients/channel-access-token/lib/Configuration.php
@@ -115,7 +115,7 @@ class Configuration
      *
      * @var string
      */
-    protected $userAgent = 'OpenAPI-Generator/1.0.0/PHP';
+    protected $userAgent = 'LINE-BotSDK-PHP/8';
 
     /**
      * Debug switch (default set to false)
diff --git a/src/clients/insight/lib/Configuration.php b/src/clients/insight/lib/Configuration.php
index 309840d1..4dea6283 100644
--- a/src/clients/insight/lib/Configuration.php
+++ b/src/clients/insight/lib/Configuration.php
@@ -115,7 +115,7 @@ class Configuration
      *
      * @var string
      */
-    protected $userAgent = 'OpenAPI-Generator/1.0.0/PHP';
+    protected $userAgent = 'LINE-BotSDK-PHP/8';
 
     /**
      * Debug switch (default set to false)
diff --git a/src/clients/liff/lib/Configuration.php b/src/clients/liff/lib/Configuration.php
index 8a1f1946..f9ad198a 100644
--- a/src/clients/liff/lib/Configuration.php
+++ b/src/clients/liff/lib/Configuration.php
@@ -115,7 +115,7 @@ class Configuration
      *
      * @var string
      */
-    protected $userAgent = 'OpenAPI-Generator/1.0.0/PHP';
+    protected $userAgent = 'LINE-BotSDK-PHP/8';
 
     /**
      * Debug switch (default set to false)
diff --git a/src/clients/manage-audience/lib/Configuration.php b/src/clients/manage-audience/lib/Configuration.php
index d73452c7..5243878c 100644
--- a/src/clients/manage-audience/lib/Configuration.php
+++ b/src/clients/manage-audience/lib/Configuration.php
@@ -115,7 +115,7 @@ class Configuration
      *
      * @var string
      */
-    protected $userAgent = 'OpenAPI-Generator/1.0.0/PHP';
+    protected $userAgent = 'LINE-BotSDK-PHP/8';
 
     /**
      * Debug switch (default set to false)
diff --git a/src/clients/messaging-api/lib/Configuration.php b/src/clients/messaging-api/lib/Configuration.php
index 12b09413..3e95ab19 100644
--- a/src/clients/messaging-api/lib/Configuration.php
+++ b/src/clients/messaging-api/lib/Configuration.php
@@ -115,7 +115,7 @@ class Configuration
      *
      * @var string
      */
-    protected $userAgent = 'OpenAPI-Generator/1.0.0/PHP';
+    protected $userAgent = 'LINE-BotSDK-PHP/8';
 
     /**
      * Debug switch (default set to false)
diff --git a/tools/gen-oas-client.sh b/tools/gen-oas-client.sh
index 83664005..e12a006b 100755
--- a/tools/gen-oas-client.sh
+++ b/tools/gen-oas-client.sh
@@ -19,6 +19,7 @@ for schema in "${CLIENT_SCHEMAS[@]}"; do
     -i $REPO_ROOT_DIR/line-openapi/$schema.yml \
     -g php \
     -o $REPO_ROOT_DIR/src/clients/$schema \
+    --http-user-agent LINE-BotSDK-PHP/8 \
     --additional-properties="invokerPackage=LINE\Clients\\$camelSchemaName" \
     --additional-properties="variableNamingConvention=camelCase"
 done