diff --git a/co-authors-plus.php b/co-authors-plus.php
index 948d3b3a..66fd079c 100755
--- a/co-authors-plus.php
+++ b/co-authors-plus.php
@@ -56,8 +56,6 @@ class CoAuthors_Plus {
 	var $coauthors_meta_box_name   = 'coauthorsdiv';
 	var $force_guest_authors       = false;
 
-	var $gravatar_size = 25;
-
 	var $_pages_whitelist = array( 'post.php', 'post-new.php', 'edit.php' );
 
 	var $supported_post_types = array();
@@ -453,7 +451,7 @@ public function coauthors_meta_box( $post ) {
 					$avatar_url = get_avatar_url( $coauthor->ID, array( 'user_type' => $user_type ) );
 					?>
 					<li>
-						<?php echo get_avatar( $coauthor->ID, $this->gravatar_size ); ?>
+						<?php echo get_avatar( $coauthor->ID ); ?>
 						<span id="<?php echo esc_attr( 'coauthor-readonly-' . $count ); ?>" class="coauthor-tag">
 							<input type="text" name="coauthorsinput[]" readonly="readonly" value="<?php echo esc_attr( $coauthor->display_name ); ?>" />
 							<input type="text" name="coauthors[]" value="<?php echo esc_attr( $coauthor->user_login ); ?>" />
@@ -1863,11 +1861,11 @@ public function filter_pre_get_avatar_data_url( $args, $id ) {
 		$coauthor = $this->get_coauthor_by( 'id', $id );
 		if ( false !== $coauthor && isset( $coauthor->type ) && 'guest-author' === $coauthor->type ) {
 			if ( has_post_thumbnail( $id ) ) {
-				$args['url'] = get_the_post_thumbnail_url( $id, $this->gravatar_size );
+				$args['url'] = get_the_post_thumbnail_url( $id, array( $args['width'], $args['height'] ) );
 			} elseif ( isset( $coauthor->user_email ) ) {
-				$args['url'] = get_avatar_url( $coauthor->user_email );
+				$args['url'] = get_avatar_url( $coauthor->user_email, $args );
 			} else {
-				$args['url'] = get_avatar_url( '' ); // Fallback to default.
+				$args['url'] = get_avatar_url( '', $args ); // Fallback to default.
 			}
 		}
 		return $args;
diff --git a/css/co-authors-plus.css b/css/co-authors-plus.css
index 61ad9d5c..a01acce8 100644
--- a/css/co-authors-plus.css
+++ b/css/co-authors-plus.css
@@ -102,6 +102,8 @@
 		}
 		#coauthors-readonly ul li .avatar {
 			float: left;
+			width: 25px;
+			height: 25px;
 		}
 		#coauthors-readonly ul li .coauthor-tag {
 			display:block;