diff --git a/author.php b/author.php
index bf77d7be8..36df061f7 100644
--- a/author.php
+++ b/author.php
@@ -41,15 +41,15 @@ get_header(); ?>
 			<?php
 			// If a user has filled out their description, show a bio on their entries.
 			if ( get_the_author_meta( 'description' ) ) : ?>
-			<div id="author-info">
-				<div id="author-avatar">
+			<div class="author-info">
+				<div class="author-avatar">
 					<?php echo get_avatar( get_the_author_meta( 'user_email' ), apply_filters( 'twentytwelve_author_bio_avatar_size', 60 ) ); ?>
-				</div><!-- #author-avatar -->
-				<div id="author-description">
+				</div><!-- .author-avatar -->
+				<div class="author-description">
 					<h2><?php printf( __( 'About %s', 'twentytwelve' ), get_the_author() ); ?></h2>
 					<p><?php the_author_meta( 'description' ); ?></p>
-				</div><!-- #author-description	-->
-			</div><!-- #author-info -->
+				</div><!-- .author-description	-->
+			</div><!-- .author-info -->
 			<?php endif; ?>
 
 			<?php /* Start the Loop */ ?>
diff --git a/content.php b/content.php
index 7191a463e..90cd694be 100644
--- a/content.php
+++ b/content.php
@@ -45,20 +45,20 @@
 			<?php twentytwelve_entry_meta(); ?>
 			<?php edit_post_link( __( 'Edit', 'twentytwelve' ), '<span class="edit-link">', '</span>' ); ?>
 			<?php if ( is_singular() && get_the_author_meta( 'description' ) && is_multi_author() ) : // If a user has filled out their description and this is a multi-author blog, show a bio on their entries. ?>
-				<div id="author-info">
-					<div id="author-avatar">
+				<div class="author-info">
+					<div class="author-avatar">
 						<?php echo get_avatar( get_the_author_meta( 'user_email' ), apply_filters( 'twentytwelve_author_bio_avatar_size', 68 ) ); ?>
-					</div><!-- #author-avatar -->
-					<div id="author-description">
+					</div><!-- .author-avatar -->
+					<div class="author-description">
 						<h2><?php printf( __( 'About %s', 'twentytwelve' ), get_the_author() ); ?></h2>
 						<p><?php the_author_meta( 'description' ); ?></p>
-						<div id="author-link">
+						<div class="author-link">
 							<a href="<?php echo esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ); ?>" rel="author">
 								<?php printf( __( 'View all posts by %s <span class="meta-nav">&rarr;</span>', 'twentytwelve' ), get_the_author() ); ?>
 							</a>
-						</div><!-- #author-link	-->
-					</div><!-- #author-description -->
-				</div><!-- #author-info -->
+						</div><!-- .author-link	-->
+					</div><!-- .author-description -->
+				</div><!-- .author-info -->
 			<?php endif; ?>
 		</footer><!-- .entry-meta -->
 	</article><!-- #post -->
diff --git a/rtl.css b/rtl.css
index 3e9a7df1b..0a8969449 100644
--- a/rtl.css
+++ b/rtl.css
@@ -43,10 +43,10 @@ td {
 }
 
 /* Author profiles */
-#author-avatar {
+.author-avatar {
 	float: right;
 }
-#author-description {
+.author-description {
 	float: right;
 	margin-right: 15px;
 	margin-right: 1.071428571rem;
diff --git a/style.css b/style.css
index 4c7a4c997..24cc4b81d 100644
--- a/style.css
+++ b/style.css
@@ -324,7 +324,7 @@ video {
 .comment-content img,
 .widget img,
 img.header-image,
-#author-avatar img,
+.author-avatar img,
 img.wp-post-image {
 	/* Add fancy borders to all WordPress-added images but not things like badges and icons and the like */
 	border-radius: 3px;
@@ -410,7 +410,7 @@ img.wp-smiley,
 	margin-bottom: 24px;
 	margin-bottom: 1.714285714rem;
 }
-#author-info {
+.author-info {
 	border-top: 1px solid #ededed;
 	margin: 24px 0;
 	margin: 1.714285714rem 0;
@@ -418,18 +418,18 @@ img.wp-smiley,
 	padding-top: 1.714285714rem;
 	overflow: hidden;
 }
-#author-description p {
+.author-description p {
 	color: #777;
 	font-size: 13px;
 	font-size: 0.928571429rem;
 	line-height: 1.846153846;
 }
-.author.archive #author-info {
+.author.archive .author-info {
 	border-top: 0;
 	margin: 0 0 48px;
 	margin: 0 0 3.428571429rem;
 }
-.author.archive #author-avatar {
+.author.archive .author-avatar {
 	margin-top: 0;
 }
 
@@ -1340,12 +1340,12 @@ img#wpstats {
 
 /* Minimum width of 600 pixels. */
 @media screen and (min-width: 600px) {
-	#author-avatar {
+	.author-avatar {
 		float: left;
 		margin-top: 8px;
 		margin-top: 0.571428571rem;
 	}
-	#author-description {
+	.author-description {
 		float: right;
 		width: 80%;
 	}
@@ -1541,7 +1541,7 @@ img#wpstats {
 	}
 	.entry-content img,
 	.comment-content img,
-	#author-avatar img,
+	.author-avatar img,
 	img.wp-post-image {
 		border-radius: 0;
 		box-shadow: none;
@@ -1567,7 +1567,7 @@ img#wpstats {
 		font-size: 10pt;
 		text-align: left;
 	}
-	#author-avatar,
+	.author-avatar,
 	#colophon,
 	#respond,
 	.commentlist .comment-edit-link,
@@ -1615,7 +1615,7 @@ img#wpstats {
 		color: #444;
 		font-size: 10pt;
 	}
-	#author-description {
+	.author-description {
 		float: none;
 		width: auto;
 	}