diff --git a/less/_02-layout.less b/less/_02-layout.less
index 2cef301..5907a00 100644
--- a/less/_02-layout.less
+++ b/less/_02-layout.less
@@ -17,7 +17,7 @@
 /* blocks that must contain floats */
 .clearfix,
 .line {
-	&:after {
+	&::after {
 		content: "";
 		display: table;
 		clear: both;
diff --git a/less/_08-print.less b/less/_08-print.less
index 06b701d..0e7012f 100644
--- a/less/_08-print.less
+++ b/less/_08-print.less
@@ -87,12 +87,12 @@
 	}
 	
 	/* displaying URLs */
-	a[href]:after {
+	a[href]::after {
 		content: " (" attr(href) ")";
 	}
 	
-	a[href^="javascript:"]:after,
-	a[href^="#"]:after {
+	a[href^="javascript:"]::after,
+	a[href^="#"]::after {
 		content: "";
 	}
 }
diff --git a/less/_10-styling.less b/less/_10-styling.less
index 79553fb..2f0531b 100644
--- a/less/_10-styling.less
+++ b/less/_10-styling.less
@@ -51,7 +51,7 @@ blockquote {
 	padding-left: 3em;
 }
 
-blockquote:before {
+blockquote::before {
 	content: "\201C";
 	position: absolute;
 	left: 0;
@@ -68,7 +68,7 @@ blockquote > footer {
 	color: rgba(0, 0, 0, .7);
 }
 
-blockquote > footer:before {
+blockquote > footer::before {
 	content: "\2014 \0020";
 }
 
diff --git a/less/_11-wordpress.less b/less/_11-wordpress.less
index 429837c..805dc82 100644
--- a/less/_11-wordpress.less
+++ b/less/_11-wordpress.less
@@ -76,7 +76,7 @@ Description: Reset styles for WordPress usage of KNACSS
 .comment-content {
 	clear: both;
 	
-	&:after, &:before {
+	&::after, &::before {
 		content: "";
 		display: table;
 	}
diff --git a/sass/_02-layout.scss b/sass/_02-layout.scss
index 5a6774a..7183af8 100644
--- a/sass/_02-layout.scss
+++ b/sass/_02-layout.scss
@@ -17,7 +17,7 @@
 /* blocks that must contain floats */
 .clearfix,
 .line {
-	&:after {
+	&::after {
 		content: "";
 		display: table;
 		clear: both;
diff --git a/sass/_08-print.scss b/sass/_08-print.scss
index 2311ac7..4827f45 100644
--- a/sass/_08-print.scss
+++ b/sass/_08-print.scss
@@ -77,7 +77,7 @@
 	h3,
 	.h3-like,
 	caption {
-		page-break-after: avoid; 
+		page-break-after: avoid;
 	}
 	
 	a {
@@ -86,12 +86,12 @@
 	}
 	
 	/* displaying URLs */
-	a[href]:after {
+	a[href]::after {
 		content: " (" attr(href) ")";
 	}
 	
-	a[href^="javascript:"]:after,
-	a[href^="#"]:after {
+	a[href^="javascript:"]::after,
+	a[href^="#"]::after {
 		content: "";
 	}
 }
diff --git a/sass/_10-styling.scss b/sass/_10-styling.scss
index 7a82d34..74b90e5 100644
--- a/sass/_10-styling.scss
+++ b/sass/_10-styling.scss
@@ -49,7 +49,7 @@ blockquote {
 	padding-left: 3em;
 }
 
-blockquote:before {
+blockquote::before {
 	content: "\201C";
 	position: absolute;
 	left: 0;
@@ -66,7 +66,7 @@ blockquote > footer {
 	color: rgba(0, 0, 0, .7);
 }
 
-blockquote > footer:before {
+blockquote > footer::before {
 	content: "\2014 \0020";
 }
 
diff --git a/sass/_11-wordpress.scss b/sass/_11-wordpress.scss
index 429837c..805dc82 100644
--- a/sass/_11-wordpress.scss
+++ b/sass/_11-wordpress.scss
@@ -76,7 +76,7 @@ Description: Reset styles for WordPress usage of KNACSS
 .comment-content {
 	clear: both;
 	
-	&:after, &:before {
+	&::after, &::before {
 		content: "";
 		display: table;
 	}