diff --git a/class-gwiz-gf-code-chest.php b/class-gwiz-gf-code-chest.php
index 79b1bd6..b011d8d 100644
--- a/class-gwiz-gf-code-chest.php
+++ b/class-gwiz-gf-code-chest.php
@@ -679,7 +679,7 @@ public function prefix_css_selectors( $css, $prefix ) {
 		 * Find all CSS selectors, but ignore all `@` rules such as @font-face, @media, etc. as they are
 		 * defined globally and not can't be scoped to a certion "parent" selector.
 		 */
-		return preg_replace_callback('/^\s*(?!@)([^\r\n,{}]+)(,(?=[^}]*{)|\s*{)/m', function( $matches ) use ( $prefix ) {
+		return preg_replace_callback('/^\s*(?!@)([^\r\n,{}\/]+)(,(?=[^}]*{)|\s*{)/m', function( $matches ) use ( $prefix ) {
 			return $prefix . ' ' . trim( $matches[1] ) . $matches[2];
 		}, $css);
 	}