diff --git a/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js b/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js
index f7f2b3cd40..91dff3870a 100644
--- a/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js
+++ b/src/wp-includes/js/tinymce/plugins/wordpress/plugin.js
@@ -297,6 +297,8 @@ tinymce.PluginManager.add( 'wordpress', function( editor ) {
 			} else if ( env.ie < 8 ) {
 				bodyClass.push('ie7');
 			}
+		} else if ( env.webkit ) {
+			bodyClass.push('webkit');
 		}
 
 		bodyClass.push('wp-editor');
diff --git a/src/wp-includes/js/tinymce/skins/wordpress/wp-content.css b/src/wp-includes/js/tinymce/skins/wordpress/wp-content.css
index e55bdabe09..ec5182cb55 100644
--- a/src/wp-includes/js/tinymce/skins/wordpress/wp-content.css
+++ b/src/wp-includes/js/tinymce/skins/wordpress/wp-content.css
@@ -17,6 +17,13 @@ body {
 	margin: 10px;
 }
 
+/* When font-weight is different than the default browser style,
+Chrome and Safari replace <strong> and <b> with spans with inline styles on pasting?! */
+body.webkit strong,
+body.webkit b {
+	font-weight: bold !important;
+}
+
 /* DFW mode */
 html.wp-fullscreen,
 html.wp-fullscreen body {