diff --git a/library/Icinga/Less/ColorProp.php b/library/Icinga/Less/ColorProp.php
index 9c38d0ea1..f10115d75 100644
--- a/library/Icinga/Less/ColorProp.php
+++ b/library/Icinga/Less/ColorProp.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/ColorPropOrVariable.php b/library/Icinga/Less/ColorPropOrVariable.php
index 93652ed87..371cca47f 100644
--- a/library/Icinga/Less/ColorPropOrVariable.php
+++ b/library/Icinga/Less/ColorPropOrVariable.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/LightMode.php b/library/Icinga/Less/LightMode.php
index 4bf2ca608..30197614a 100644
--- a/library/Icinga/Less/LightMode.php
+++ b/library/Icinga/Less/LightMode.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/LightModeCall.php b/library/Icinga/Less/LightModeCall.php
index 49e4b0f18..65cdbfe0d 100644
--- a/library/Icinga/Less/LightModeCall.php
+++ b/library/Icinga/Less/LightModeCall.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/LightModeDefinition.php b/library/Icinga/Less/LightModeDefinition.php
index fc7f96a1e..63e1baaf5 100644
--- a/library/Icinga/Less/LightModeDefinition.php
+++ b/library/Icinga/Less/LightModeDefinition.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/LightModeTrait.php b/library/Icinga/Less/LightModeTrait.php
index 53d706bac..efdffdc93 100644
--- a/library/Icinga/Less/LightModeTrait.php
+++ b/library/Icinga/Less/LightModeTrait.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/LightModeVisitor.php b/library/Icinga/Less/LightModeVisitor.php
index eb393e934..2b06234f4 100644
--- a/library/Icinga/Less/LightModeVisitor.php
+++ b/library/Icinga/Less/LightModeVisitor.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;
 
diff --git a/library/Icinga/Less/Visitor.php b/library/Icinga/Less/Visitor.php
index 265009473..87036bef5 100644
--- a/library/Icinga/Less/Visitor.php
+++ b/library/Icinga/Less/Visitor.php
@@ -1,4 +1,5 @@
 <?php
+/* Icinga Web 2 | (c) 2022 Icinga Development Team | GPLv2+ */
 
 namespace Icinga\Less;