diff --git a/library/Icinga/Web/StyleSheet.php b/library/Icinga/Web/StyleSheet.php
index 7e1993609..aba89b4cc 100644
--- a/library/Icinga/Web/StyleSheet.php
+++ b/library/Icinga/Web/StyleSheet.php
@@ -78,7 +78,8 @@ class StyleSheet
         'css/icinga/responsive.less',
         'css/icinga/modal.less',
         'css/icinga/audit.less',
-        'css/icinga/health.less'
+        'css/icinga/health.less',
+        'css/icinga/php-diff.less'
     ];
 
     /**
diff --git a/public/css/icinga/php-diff.less b/public/css/icinga/php-diff.less
new file mode 100644
index 000000000..d8f6a800b
--- /dev/null
+++ b/public/css/icinga/php-diff.less
@@ -0,0 +1,17 @@
+@diff-bg-color: transparent;
+@diff-text-color: @text-color;
+
+@diff-bg-color-ins-base: @color-up;
+@diff-bg-color-del-base: @color-down;
+@diff-bg-color-rep-base: @color-warning;
+
+@diff-border-color: @gray-light;
+
+@light-mode: {
+  :root {
+    --diff-bg-color: var(--body-bg-color);
+    --diff-text-color: var(--text-color);
+
+    --diff-border-color: var(--gray-light);
+  }
+};