diff --git a/backport-changelog/6.8/7069.md b/backport-changelog/6.8/7069.md
index 69edbde58902d1..3e734637ddbb2f 100644
--- a/backport-changelog/6.8/7069.md
+++ b/backport-changelog/6.8/7069.md
@@ -3,3 +3,4 @@ https://github.com/WordPress/wordpress-develop/pull/7069
 * https://github.com/WordPress/gutenberg/pull/63401
 * https://github.com/WordPress/gutenberg/pull/66918
 * https://github.com/WordPress/gutenberg/pull/67018
+* https://github.com/WordPress/gutenberg/pull/67552
diff --git a/lib/compat/wordpress-6.8/blocks.php b/lib/compat/wordpress-6.8/blocks.php
index 4d4bdee2bb393b..e0f5082bfce8dc 100644
--- a/lib/compat/wordpress-6.8/blocks.php
+++ b/lib/compat/wordpress-6.8/blocks.php
@@ -71,6 +71,10 @@ function gutenberg_stabilize_experimental_block_supports( $args ) {
 		}
 
 		$stabilize_config = function ( $unstable_config, $stable_support_key ) use ( $experimental_support_properties, $common_experimental_properties ) {
+			if ( ! is_array( $unstable_config ) ) {
+				return $unstable_config;
+			}
+
 			$stable_config = array();
 			foreach ( $unstable_config as $key => $value ) {
 				// Get stable key from support-specific map, common properties map, or keep original.
@@ -116,18 +120,19 @@ function gutenberg_stabilize_experimental_block_supports( $args ) {
 				( $key_positions[ $support ] ?? PHP_INT_MAX ) <
 				( $key_positions[ $stable_support_key ] ?? PHP_INT_MAX );
 
-			if ( is_array( $args['supports'][ $stable_support_key ] ) ) {
-				/*
-				 * To merge the alternative support config effectively, it also needs to be
-				 * stabilized before merging to keep stabilized and experimental flags in
-				 * sync.
-				 */
-				$args['supports'][ $stable_support_key ] = $stabilize_config( $args['supports'][ $stable_support_key ], $stable_support_key );
-				$stable_config                           = $experimental_first
+			/*
+			 * To merge the alternative support config effectively, it also needs to be
+			 * stabilized before merging to keep stabilized and experimental flags in
+			 * sync.
+			 */
+			$args['supports'][ $stable_support_key ] = $stabilize_config( $args['supports'][ $stable_support_key ], $stable_support_key );
+			// Prevents reprocessing this support as it was stabilized above.
+			$done[ $stable_support_key ] = true;
+
+			if ( is_array( $stable_config ) && is_array( $args['supports'][ $stable_support_key ] ) ) {
+				$stable_config = $experimental_first
 					? array_merge( $stable_config, $args['supports'][ $stable_support_key ] )
 					: array_merge( $args['supports'][ $stable_support_key ], $stable_config );
-				// Prevents reprocessing this support as it was merged above.
-				$done[ $stable_support_key ] = true;
 			} else {
 				$stable_config = $experimental_first
 					? $args['supports'][ $stable_support_key ]
diff --git a/phpunit/block-supports/border-test.php b/phpunit/block-supports/border-test.php
index 6ec43b369d9a2a..510633b48aab59 100644
--- a/phpunit/block-supports/border-test.php
+++ b/phpunit/block-supports/border-test.php
@@ -730,4 +730,104 @@ public function test_should_stabilize_border_supports_using_order_based_merge()
 		);
 		$this->assertSame( $expected, $actual, 'Merged stabilized border block support config does not match when stable keys are first.' );
 	}
+
+	/**
+	 * Tests that boolean border support configurations are handled correctly.
+	 *
+	 * @dataProvider data_boolean_border_supports
+	 *
+	 * @param array         $supports       The supports configuration to test.
+	 * @param boolean|array $expected_value The expected final border support value.
+	 */
+	public function test_should_handle_boolean_border_supports( $supports, $expected_value ) {
+		$args = array(
+			'supports' => $supports,
+		);
+
+		$actual = gutenberg_stabilize_experimental_block_supports( $args );
+
+		$this->assertSame( $expected_value, $actual['supports']['border'] );
+	}
+
+	/**
+	 * Data provider for boolean border support tests.
+	 *
+	 * @return array Test parameters.
+	 */
+	public function data_boolean_border_supports() {
+		return array(
+			'experimental true only'                   => array(
+				array(
+					'__experimentalBorder' => true,
+				),
+				true,
+			),
+			'experimental false only'                  => array(
+				array(
+					'__experimentalBorder' => false,
+				),
+				false,
+			),
+			'experimental true before stable false'    => array(
+				array(
+					'__experimentalBorder' => true,
+					'border'               => false,
+				),
+				false,
+			),
+			'stable true before experimental false'    => array(
+				array(
+					'border'               => true,
+					'__experimentalBorder' => false,
+				),
+				false,
+			),
+			'experimental array before stable boolean' => array(
+				array(
+					'__experimentalBorder' => array(
+						'color' => true,
+						'width' => true,
+					),
+					'border'               => false,
+				),
+				false,
+			),
+			'stable array before experimental boolean' => array(
+				array(
+					'border'               => array(
+						'color' => true,
+						'width' => true,
+					),
+					'__experimentalBorder' => true,
+				),
+				true,
+			),
+			'experimental boolean before stable array' => array(
+				array(
+					'__experimentalBorder' => true,
+					'border'               => array(
+						'color' => true,
+						'width' => true,
+					),
+				),
+				array(
+					'color' => true,
+					'width' => true,
+				),
+			),
+			'stable boolean before experimental array' => array(
+				array(
+					'border'               => false,
+					'__experimentalBorder' => array(
+						'color' => true,
+						'width' => true,
+					),
+				),
+				array(
+					'color' => true,
+					'width' => true,
+				),
+			),
+		);
+	}
 }