diff --git a/packages/block-library/src/archives/index.js b/packages/block-library/src/archives/index.js
index c2917ebfa873eb..9d0f780d464405 100644
--- a/packages/block-library/src/archives/index.js
+++ b/packages/block-library/src/archives/index.js
@@ -25,7 +25,7 @@ export const settings = {
 
 	getEditWrapperProps( attributes ) {
 		const { align } = attributes;
-		if ( 'left' === align || 'right' === align || 'center' === align ) {
+		if ( [ 'left', 'center', 'right' ].includes( align ) ) {
 			return { 'data-align': align };
 		}
 	},
diff --git a/packages/block-library/src/archives/index.php b/packages/block-library/src/archives/index.php
index 5386a4fea15a4f..adcc61c233b7ac 100644
--- a/packages/block-library/src/archives/index.php
+++ b/packages/block-library/src/archives/index.php
@@ -16,7 +16,16 @@
  */
 function render_block_core_archives( $attributes ) {
 	$show_post_count = ! empty( $attributes['showPostCounts'] );
-	$class           = "wp-block-archives align{$attributes['align']}";
+
+	$class = 'wp-block-archives';
+
+	if ( isset( $attributes['align'] ) ) {
+		$class .= " align{$attributes['align']}";
+	}
+
+	if ( isset( $attributes['className'] ) ) {
+		$class .= " {$attributes['className']}";
+	}
 
 	if ( ! empty( $attributes['displayAsDropdown'] ) ) {
 
@@ -111,17 +120,19 @@ function register_block_core_archives() {
 		'core/archives',
 		array(
 			'attributes'      => array(
-				'showPostCounts'    => array(
-					'type'    => 'boolean',
-					'default' => false,
+				'align'             => array(
+					'type' => 'string',
+				),
+				'className'         => array(
+					'type' => 'string',
 				),
 				'displayAsDropdown' => array(
 					'type'    => 'boolean',
 					'default' => false,
 				),
-				'align'             => array(
-					'type'    => 'string',
-					'default' => 'none',
+				'showPostCounts'    => array(
+					'type'    => 'boolean',
+					'default' => false,
 				),
 			),
 			'render_callback' => 'render_block_core_archives',
diff --git a/test/integration/full-content/fixtures/core__archives.html b/test/integration/full-content/fixtures/core__archives.html
index 68bda3aaef3fdf..dbed6fec172dc5 100644
--- a/test/integration/full-content/fixtures/core__archives.html
+++ b/test/integration/full-content/fixtures/core__archives.html
@@ -1 +1 @@
-<!-- wp:archives {"showPostCounts":false,"displayAsDropdown":false} /-->
\ No newline at end of file
+<!-- wp:archives {"displayAsDropdown":false,"showPostCounts":false} /-->
\ No newline at end of file
diff --git a/test/integration/full-content/fixtures/core__archives.json b/test/integration/full-content/fixtures/core__archives.json
index 0caf2ec732a3d1..ad43f4051a739e 100644
--- a/test/integration/full-content/fixtures/core__archives.json
+++ b/test/integration/full-content/fixtures/core__archives.json
@@ -4,9 +4,8 @@
         "name": "core/archives",
         "isValid": true,
         "attributes": {
-            "showPostCounts": false,
             "displayAsDropdown": false,
-            "align": "none"
+            "showPostCounts": false
         },
         "innerBlocks": [],
         "originalContent": ""
diff --git a/test/integration/full-content/fixtures/core__archives.parsed.json b/test/integration/full-content/fixtures/core__archives.parsed.json
index f883870399030b..fab690ff93afdf 100644
--- a/test/integration/full-content/fixtures/core__archives.parsed.json
+++ b/test/integration/full-content/fixtures/core__archives.parsed.json
@@ -2,8 +2,8 @@
     {
         "blockName": "core/archives",
         "attrs": {
-            "showPostCounts": false,
-            "displayAsDropdown": false
+            "displayAsDropdown": false,
+            "showPostCounts": false
         },
         "innerBlocks": [],
         "innerHTML": ""
diff --git a/test/integration/full-content/fixtures/core__archives__showPostCounts.html b/test/integration/full-content/fixtures/core__archives__showPostCounts.html
index bd1c93d1e1d336..cce02a6a1a784f 100644
--- a/test/integration/full-content/fixtures/core__archives__showPostCounts.html
+++ b/test/integration/full-content/fixtures/core__archives__showPostCounts.html
@@ -1 +1 @@
-<!-- wp:archives {"showPostCounts":true,"displayAsDropdown":false} /-->
\ No newline at end of file
+<!-- wp:archives {"displayAsDropdown":false,"showPostCounts":true} /-->
\ No newline at end of file
diff --git a/test/integration/full-content/fixtures/core__archives__showPostCounts.json b/test/integration/full-content/fixtures/core__archives__showPostCounts.json
index 76d086c472d07f..0c1514e413a612 100644
--- a/test/integration/full-content/fixtures/core__archives__showPostCounts.json
+++ b/test/integration/full-content/fixtures/core__archives__showPostCounts.json
@@ -4,9 +4,8 @@
         "name": "core/archives",
         "isValid": true,
         "attributes": {
-            "showPostCounts": true,
             "displayAsDropdown": false,
-            "align": "none"
+            "showPostCounts": true
         },
         "innerBlocks": [],
         "originalContent": ""
diff --git a/test/integration/full-content/fixtures/core__archives__showPostCounts.parsed.json b/test/integration/full-content/fixtures/core__archives__showPostCounts.parsed.json
index b016ecf02288de..cd58cbf96924db 100644
--- a/test/integration/full-content/fixtures/core__archives__showPostCounts.parsed.json
+++ b/test/integration/full-content/fixtures/core__archives__showPostCounts.parsed.json
@@ -2,8 +2,8 @@
     {
         "blockName": "core/archives",
         "attrs": {
-            "showPostCounts": true,
-            "displayAsDropdown": false
+            "displayAsDropdown": false,
+            "showPostCounts": true
         },
         "innerBlocks": [],
         "innerHTML": ""
diff --git a/test/integration/full-content/server-registered.json b/test/integration/full-content/server-registered.json
index ae3a5650908577..0434a63b6634be 100644
--- a/test/integration/full-content/server-registered.json
+++ b/test/integration/full-content/server-registered.json
@@ -1 +1 @@
-{"core\/block":{"attributes":{"ref":{"type":"number"}}},"core\/latest-comments":{"attributes":{"className":{"type":"string"},"commentsToShow":{"type":"number","default":5,"minimum":1,"maximum":100},"displayAvatar":{"type":"boolean","default":true},"displayDate":{"type":"boolean","default":true},"displayExcerpt":{"type":"boolean","default":true},"align":{"type":"string","enum":["center","left","right","wide","full",""]}}},"core\/archives":{"attributes":{"showPostCounts":{"type":"boolean","default":false},"displayAsDropdown":{"type":"boolean","default":false},"align":{"type":"string","default":"none"}}},"core\/latest-posts":{"attributes":{"categories":{"type":"string"},"className":{"type":"string"},"postsToShow":{"type":"number","default":5},"displayPostDate":{"type":"boolean","default":false},"postLayout":{"type":"string","default":"list"},"columns":{"type":"number","default":3},"align":{"type":"string"},"order":{"type":"string","default":"desc"},"orderBy":{"type":"string","default":"date"}}}}
\ No newline at end of file
+{"core\/block":{"attributes":{"ref":{"type":"number"}}},"core\/latest-comments":{"attributes":{"className":{"type":"string"},"commentsToShow":{"type":"number","default":5,"minimum":1,"maximum":100},"displayAvatar":{"type":"boolean","default":true},"displayDate":{"type":"boolean","default":true},"displayExcerpt":{"type":"boolean","default":true},"align":{"type":"string","enum":["center","left","right","wide","full",""]}}},"core\/archives":{"attributes":{"align":{"type":"string"},"className":{"type":"string"},"displayAsDropdown":{"type":"boolean","default":false},"showPostCounts":{"type":"boolean","default":false}}},"core\/latest-posts":{"attributes":{"categories":{"type":"string"},"className":{"type":"string"},"postsToShow":{"type":"number","default":5},"displayPostDate":{"type":"boolean","default":false},"postLayout":{"type":"string","default":"list"},"columns":{"type":"number","default":3},"align":{"type":"string"},"order":{"type":"string","default":"desc"},"orderBy":{"type":"string","default":"date"}}}}