Index: src/wp-admin/css/edit.css
===================================================================
--- src/wp-admin/css/edit.css	(revision 29763)
+++ src/wp-admin/css/edit.css	(working copy)
@@ -1431,7 +1431,7 @@
 		padding: 10px 20px;
 	}
 
-	a.wp-switch-editor {
+	button.wp-switch-editor {
 		font-size: 16px;
 		line-height: 1em;
 		margin: 3px 0 0 7px;
@@ -1438,6 +1438,11 @@
 		padding: 12px 15px;
 	}
 
+	.tmce-active button.switch-tmce,
+	.html-active button.switch-html {
+		padding: 12px 15px;
+	}
+
 	#wp-content-media-buttons a {
 		font-size: 16px;
 		line-height: 37px;
Index: src/wp-includes/class-wp-editor.php
===================================================================
--- src/wp-includes/class-wp-editor.php	(revision 29763)
+++ src/wp-includes/class-wp-editor.php	(working copy)
@@ -177,8 +177,8 @@
 				$switch_class = 'tmce-active';
 			}
 
-			$buttons .= '<a id="' . $editor_id . '-html" class="wp-switch-editor switch-html" onclick="switchEditors.switchto(this);">' . _x( 'Text', 'Name for the Text editor tab (formerly HTML)' ) . "</a>\n";
-			$buttons .= '<a id="' . $editor_id . '-tmce" class="wp-switch-editor switch-tmce" onclick="switchEditors.switchto(this);">' . __('Visual') . "</a>\n";
+			$buttons .= '<button type="button" id="' . $editor_id . '-tmce" class="wp-switch-editor switch-tmce" onclick="switchEditors.switchto(this);">' . __('Visual') . "</button>\n";
+			$buttons .= '<button type="button" id="' . $editor_id . '-html" class="wp-switch-editor switch-html" onclick="switchEditors.switchto(this);">' . _x( 'Text', 'Name for the Text editor tab (formerly HTML)' ) . "</button>\n";
 		}
 
 		$wrap_class = 'wp-core-ui wp-editor-wrap ' . $switch_class;
Index: src/wp-includes/css/buttons.css
===================================================================
--- src/wp-includes/css/buttons.css	(revision 29763)
+++ src/wp-includes/css/buttons.css	(working copy)
@@ -149,7 +149,8 @@
 
 .wp-core-ui .button.focus,
 .wp-core-ui .button:focus,
-.wp-core-ui .button-secondary:focus {
+.wp-core-ui .button-secondary:focus,
+.wp-core-ui .wp-editor-tabs button:focus {
 	-webkit-box-shadow:
 		0 0 0 1px #5b9dd9,
 		0 0 2px 1px rgba(30, 140, 190, .8);
Index: src/wp-includes/css/editor.css
===================================================================
--- src/wp-includes/css/editor.css	(revision 29763)
+++ src/wp-includes/css/editor.css	(working copy)
@@ -819,17 +819,18 @@
 }
 
 .wp-switch-editor {
-	background: #ebebeb;
+	float: left;
+	box-sizing: content-box;
+	height: 19px;
 	border: 1px solid #dedede;
-	color: #777;
-	cursor: pointer;
-	float: right;
-	font: 13px/19px "Open Sans", sans-serif;
-	height: 19px;
 	margin: 5px 0 0 5px;
 	padding: 3px 8px 4px;
 	position: relative;
 	top: 1px;
+	background: #ebebeb;
+	color: #777;
+	cursor: pointer;
+	font: 13px/19px "Open Sans", sans-serif;
 }
 
 .wp-switch-editor:active {
@@ -854,6 +855,7 @@
 	background: #f5f5f5;
 	color: #555;
 	height: 20px;
+	padding: 2px 8px 5px;
 	border-bottom: none;
 }