diff --git a/.stylelintrc.json b/.stylelintrc.json
index fed704b99..9cc074a51 100644
--- a/.stylelintrc.json
+++ b/.stylelintrc.json
@@ -7,7 +7,6 @@
 	"rules": {
 		"declaration-property-unit-disallowed-list": null,
 		"no-descending-specificity": null,
-		"selector-class-pattern": null,
-		"selector-pseudo-element-colon-notation": null
+		"selector-class-pattern": null
 	}
 }
diff --git a/resources/mmv.bootstrap/mmv.bootstrap.less b/resources/mmv.bootstrap/mmv.bootstrap.less
index 936ba85ff..b9f3bfbf7 100644
--- a/resources/mmv.bootstrap/mmv.bootstrap.less
+++ b/resources/mmv.bootstrap/mmv.bootstrap.less
@@ -32,12 +32,12 @@ body.mw-mmv-lightbox-open {
 		line-height: inherit;
 	}
 
-	.mw-mmv-view-expanded .mw-ui-icon:before {
+	.mw-mmv-view-expanded .mw-ui-icon::before {
 		/* @embed */
 		background-image: url( img/expand.svg );
 	}
 
-	.mw-mmv-view-config .mw-ui-icon:before {
+	.mw-mmv-view-config .mw-ui-icon::before {
 		/* @embed */
 		background-image: url( img/gear.svg );
 		margin-right: 0;
@@ -49,7 +49,6 @@ body.mw-mmv-lightbox-open {
 	}
 
 	.mw-mmv-view-config {
-
 		.mw-ui-icon span {
 			display: none;
 		}
diff --git a/resources/mmv.ui.download.pane/mmv.ui.download.pane.less b/resources/mmv.ui.download.pane/mmv.ui.download.pane.less
index 6a4f6a0b9..74e927b85 100644
--- a/resources/mmv.ui.download.pane/mmv.ui.download.pane.less
+++ b/resources/mmv.ui.download.pane/mmv.ui.download.pane.less
@@ -62,7 +62,7 @@
 			font-size: 16px;
 			color: #54595d;
 
-			&:before {
+			&::before {
 				display: inline-block;
 				vertical-align: middle;
 				content: ' ';
diff --git a/resources/mmv/ui/mmv.ui.metadataPanel.less b/resources/mmv/ui/mmv.ui.metadataPanel.less
index 75bd18800..57567f0aa 100644
--- a/resources/mmv/ui/mmv.ui.metadataPanel.less
+++ b/resources/mmv/ui/mmv.ui.metadataPanel.less
@@ -55,7 +55,7 @@
 		bottom: 3px;
 		background-color: @panel-above-fold-background-color; // clip text
 
-		&:before {
+		&::before {
 			.fade-out-horizontal( @panel-above-fold-background-color );
 		}
 	}
@@ -82,7 +82,7 @@
 		bottom: 13px;
 		background-color: @panel-below-fold-background-color; // clip text
 
-		&:before {
+		&::before {
 			.fade-out-horizontal( @panel-below-fold-background-color );
 		}
 	}
@@ -117,7 +117,7 @@
 	}
 }
 
-.mw-mmv-author:before {
+.mw-mmv-author::before {
 	/* @embed */
 	background-image: url( img/user-avatar.svg );
 	background-position: center center;
@@ -175,7 +175,7 @@
 			line-height: @metadatabar-below-fold-pushup-height - @space-above-credit;
 		}
 
-		&:before {
+		&::before {
 			display: inline-block;
 			vertical-align: middle;
 			height: 16px;
@@ -188,37 +188,37 @@
 			background-repeat: no-repeat;
 		}
 
-		&.mw-mmv-license-li:before {
+		&.mw-mmv-license-li::before {
 			/* @embed */
 			background-image: url( img/license.svg );
 		}
 
-		&.mw-mmv-license-li.cc-license:before {
+		&.mw-mmv-license-li.cc-license::before {
 			/* @embed */
 			background-image: url( img/cc.svg );
 		}
 
-		&.mw-mmv-license-li.pd-license:before {
+		&.mw-mmv-license-li.pd-license::before {
 			/* @embed */
 			background-image: url( img/pd.svg );
 		}
 
-		&.mw-mmv-filename-li:before {
+		&.mw-mmv-filename-li::before {
 			/* @embed */
 			background-image: url( img/file.svg );
 		}
 
-		&.mw-mmv-datetime-li:before {
+		&.mw-mmv-datetime-li::before {
 			/* @embed */
 			background-image: url( img/time.svg );
 		}
 
-		&.mw-mmv-location-li:before {
+		&.mw-mmv-location-li::before {
 			/* @embed */
 			background-image: url( img/location.svg );
 		}
 
-		&.empty:before {
+		&.empty::before {
 			background-image: none !important; /* stylelint-disable-line declaration-no-important */
 		}
 	}
@@ -306,7 +306,7 @@
 	text-align: left;
 	background-size: contain;
 
-	&:after {
+	&::after {
 		float: right;
 		text-indent: 0;
 	}
@@ -372,7 +372,7 @@
 	background-image: url( img/restrict-personality.svg );
 }
 
-.mw-mmv-restriction-trademarked:after {
+.mw-mmv-restriction-trademarked::after {
 	content: '\002122';
 }
 
diff --git a/resources/mmv/ui/mmv.ui.stripeButtons.less b/resources/mmv/ui/mmv.ui.stripeButtons.less
index 8216dc94f..90dda4c7b 100644
--- a/resources/mmv/ui/mmv.ui.stripeButtons.less
+++ b/resources/mmv/ui/mmv.ui.stripeButtons.less
@@ -23,7 +23,7 @@
 		display: none;
 	}
 
-	&:before {
+	&::before {
 		display: inline-block;
 		width: 1em;
 		height: 1em;
@@ -38,7 +38,7 @@
 		margin-right: 0.7em;
 	}
 
-	&.has-label:before {
+	&.has-label::before {
 		margin-right: 0.25em;
 	}
 
@@ -51,7 +51,7 @@
 		margin: 7px 10px;
 	}
 
-	&.mw-mmv-description-page-button.mw-mmv-repo-button-commons:before {
+	&.mw-mmv-description-page-button.mw-mmv-repo-button-commons::before {
 		/* @embed */
 		background-image: url( img/commons_white.svg );
 		width: 1.3em;
diff --git a/resources/mmv/ui/mmv.ui.truncatableTextField.less b/resources/mmv/ui/mmv.ui.truncatableTextField.less
index d5f06ac23..c678e9152 100644
--- a/resources/mmv/ui/mmv.ui.truncatableTextField.less
+++ b/resources/mmv/ui/mmv.ui.truncatableTextField.less
@@ -61,7 +61,7 @@
 			background-image: url( img/ellipsis_darkgray.svg );
 		}
 
-		&:before {
+		&::before {
 			@fade-length: 2em;
 			display: block;
 			content: '';