diff --git a/wp-content/themes/twentynineteen/style-editor.css b/wp-content/themes/twentynineteen/style-editor.css
index 54487026e2..54575e038b 100644
--- a/wp-content/themes/twentynineteen/style-editor.css
+++ b/wp-content/themes/twentynineteen/style-editor.css
@@ -1605,3 +1605,9 @@ ul.wp-block-archives li ul,
   padding-right: 0;
   width: 100%;
 }
+
+/** === Post Author Block === */
+.avatar,
+.wp-block-post-author__avatar img {
+  border-radius: 100%;
+}
diff --git a/wp-content/themes/twentynineteen/style-editor.scss b/wp-content/themes/twentynineteen/style-editor.scss
index ce8a2883f8..6bf5507d1b 100644
--- a/wp-content/themes/twentynineteen/style-editor.scss
+++ b/wp-content/themes/twentynineteen/style-editor.scss
@@ -1021,3 +1021,10 @@ $group-block-background__padding: $font__size_base;
 		width: 100%;
 	}
 }
+
+/** === Post Author Block === */
+
+.avatar,
+.wp-block-post-author__avatar img {
+	border-radius: 100%;
+}
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 96b9d494ad..2e66132c98 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-alpha-57578';
+$wp_version = '6.5-alpha-57579';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.