diff --git a/.stylelintrc.json b/.stylelintrc.json
index bb9d90f6..b99a4cd3 100644
--- a/.stylelintrc.json
+++ b/.stylelintrc.json
@@ -2,7 +2,6 @@
 	"extends": "stylelint-config-wikimedia/support-modern",
 	"rules": {
 		"no-descending-specificity": null,
-		"plugin/no-unsupported-browser-features": null,
-		"selector-pseudo-element-colon-notation": null
+		"plugin/no-unsupported-browser-features": null
 	}
 }
diff --git a/modules/ext.wikiEditor.toolbar.styles.less b/modules/ext.wikiEditor.toolbar.styles.less
index da93bfaa..45e1cae9 100644
--- a/modules/ext.wikiEditor.toolbar.styles.less
+++ b/modules/ext.wikiEditor.toolbar.styles.less
@@ -27,8 +27,8 @@ form#editform {
 }
 
 /* This disables margin collapse for the children */
-.client-js #editform:before,
-.client-js #editform:after {
+.client-js #editform::before,
+.client-js #editform::after {
 	content: ' ';
 	display: table;
 }
diff --git a/modules/jquery.wikiEditor.dialogs.config.less b/modules/jquery.wikiEditor.dialogs.config.less
index 515654a7..d9dfb854 100644
--- a/modules/jquery.wikiEditor.dialogs.config.less
+++ b/modules/jquery.wikiEditor.dialogs.config.less
@@ -131,8 +131,8 @@ body.rtl {
 }
 
 /* Self Clearing Floats */
-.wikieditor-toolbar-table-dimension-fields:after,
-.wikieditor-toolbar-dialog-wrapper:after {
+.wikieditor-toolbar-table-dimension-fields::after,
+.wikieditor-toolbar-dialog-wrapper::after {
 	visibility: hidden;
 	display: block;
 	font-size: 0;
diff --git a/modules/jquery.wikiEditor.toolbar-wikimedia.less b/modules/jquery.wikiEditor.toolbar-wikimedia.less
index 35dbc44d..dbf79fa1 100644
--- a/modules/jquery.wikiEditor.toolbar-wikimedia.less
+++ b/modules/jquery.wikiEditor.toolbar-wikimedia.less
@@ -38,7 +38,7 @@
 				/* stylelint-disable-next-line declaration-property-unit-disallowed-list */
 				line-height: 32px;
 
-				&:after {
+				&::after {
 					height: 32px;
 				}
 			}
diff --git a/modules/jquery.wikiEditor.toolbar.less b/modules/jquery.wikiEditor.toolbar.less
index d67879f1..ad56759e 100644
--- a/modules/jquery.wikiEditor.toolbar.less
+++ b/modules/jquery.wikiEditor.toolbar.less
@@ -53,7 +53,7 @@
 				padding-left: 18px;
 				padding-right: 12px;
 
-				&:before {
+				&::before {
 					content: '';
 					background: url( images/toolbar/arrow-down.svg ) center no-repeat;
 					display: block;
@@ -86,7 +86,7 @@
 					text-decoration: none;
 				}
 
-				&:before {
+				&::before {
 					body.ltr &,
 					body.rtl & {
 						transform: rotate( 0 );
@@ -162,7 +162,7 @@
 				text-decoration: none;
 				color: #222;
 
-				&:after {
+				&::after {
 					content: '';
 					background: url( images/toolbar/arrow-down.svg ) center no-repeat;
 					display: block;
@@ -174,7 +174,7 @@
 				}
 			}
 
-			&.options-shown .label:after {
+			&.options-shown .label::after {
 				transform: rotate( 180deg );
 			}