diff --git a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Access_Control-v1_0_1.xml b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Access_Control-v1_0_1.xml
index 1f929cd98..c620a5e2a 100644
--- a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Access_Control-v1_0_1.xml
+++ b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Access_Control-v1_0_1.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 FILE INFORMATION
diff --git a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Device-v1_0_1.xml b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Device-v1_0_1.xml
index b9ac618f5..2bc645747 100644
--- a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Device-v1_0_1.xml
+++ b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Device-v1_0_1.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 
 <!--
 FILE INFORMATION
diff --git a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Firmware_Update-v1_0_1.xml b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Firmware_Update-v1_0_1.xml
index 91659cacb..97442db7e 100644
--- a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Firmware_Update-v1_0_1.xml
+++ b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Firmware_Update-v1_0_1.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 FILE INFORMATION
diff --git a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Location-v1_0.xml b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Location-v1_0.xml
index b301be691..c19dc24ce 100644
--- a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Location-v1_0.xml
+++ b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Location-v1_0.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 
 <!--
 FILE INFORMATION
diff --git a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Security-v1_0.xml b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Security-v1_0.xml
index 269ae5946..50aa1dded 100644
--- a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Security-v1_0.xml
+++ b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Security-v1_0.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 FILE INFORMATION
diff --git a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Server-v1_0.xml b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Server-v1_0.xml
index ba206ad95..757034250 100644
--- a/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Server-v1_0.xml
+++ b/apps/emqx_gateway/src/lwm2m/lwm2m_xml/LWM2M_Server-v1_0.xml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8"?>
 
 <!--
 FILE INFORMATION