diff --git a/lib/block-supports/layout.php b/lib/block-supports/layout.php
index ddbd1917c30547..112f9bc978893a 100644
--- a/lib/block-supports/layout.php
+++ b/lib/block-supports/layout.php
@@ -45,24 +45,26 @@ function gutenberg_get_layout_definitions() {
 					),
 				),
 			),
+			// First/last child rules need to be after `> *` rule to take
+			// precedence when they have the same specificity.
 			'spacingStyles' => array(
 				array(
-					'selector' => ' > :first-child',
+					'selector' => ' > *',
 					'rules'    => array(
-						'margin-block-start' => '0',
+						'margin-block-start' => null,
+						'margin-block-end'   => '0',
 					),
 				),
 				array(
-					'selector' => ' > :last-child',
+					'selector' => ' > :first-child',
 					'rules'    => array(
-						'margin-block-end' => '0',
+						'margin-block-start' => '0',
 					),
 				),
 				array(
-					'selector' => ' > *',
+					'selector' => ' > :last-child',
 					'rules'    => array(
-						'margin-block-start' => null,
-						'margin-block-end'   => '0',
+						'margin-block-end' => '0',
 					),
 				),
 			),
@@ -110,24 +112,26 @@ function gutenberg_get_layout_definitions() {
 					),
 				),
 			),
+			// First/last child rules need to be after `> *` rule to take
+			// precedence when they have the same specificity.
 			'spacingStyles' => array(
 				array(
-					'selector' => ' > :first-child',
+					'selector' => ' > *',
 					'rules'    => array(
-						'margin-block-start' => '0',
+						'margin-block-start' => null,
+						'margin-block-end'   => '0',
 					),
 				),
 				array(
-					'selector' => ' > :last-child',
+					'selector' => ' > :first-child',
 					'rules'    => array(
-						'margin-block-end' => '0',
+						'margin-block-start' => '0',
 					),
 				),
 				array(
-					'selector' => ' > *',
+					'selector' => ' > :last-child',
 					'rules'    => array(
-						'margin-block-start' => null,
-						'margin-block-end'   => '0',
+						'margin-block-end' => '0',
 					),
 				),
 			),