diff --git a/extension.json b/extension.json
index 40a72180..b247e4d8 100644
--- a/extension.json
+++ b/extension.json
@@ -6,7 +6,7 @@
 	"license-name": "GPL-2.0-or-later",
 	"type": "parserhook",
 	"requires": {
-		"MediaWiki": ">= 1.35.0"
+		"MediaWiki": ">= 1.37.0"
 	},
 	"ConfigRegistry": {
 		"categorytree": "GlobalVarConfig::newInstance"
diff --git a/modules/ext.categoryTree.styles.css b/modules/ext.categoryTree.styles.css
index b97503df..ce0f8344 100644
--- a/modules/ext.categoryTree.styles.css
+++ b/modules/ext.categoryTree.styles.css
@@ -134,8 +134,6 @@
 .mw-content-rtl .mw-content-ltr .CategoryTreeEmptyBullet:empty,
 .mw-content-rtl .mw-content-ltr .CategoryTreeToggle[ data-ct-state='collapsed' ]:empty {
 	border-left: 10px solid;
-	/* The following @noflip is necessary to prevent the flipping. (T288943) */
-	/* @noflip */
 	border-right: 0 none;
 }
 
@@ -145,8 +143,6 @@
 .mw-content-ltr .mw-content-rtl .CategoryTreeEmptyBullet:empty,
 .mw-content-ltr .mw-content-rtl .CategoryTreeToggle[ data-ct-state='collapsed' ]:empty {
 	border-right: 10px solid;
-	/* The following @noflip is necessary to prevent the flipping. (T288943) */
-	/* @noflip */
 	border-left: 0 none;
 }