diff --git a/backport-changelog/6.8/7825.md b/backport-changelog/6.8/7825.md
new file mode 100644
index 00000000000000..42d09c86b7f3ba
--- /dev/null
+++ b/backport-changelog/6.8/7825.md
@@ -0,0 +1,3 @@
+https://github.com/WordPress/wordpress-develop/pull/7825
+
+* https://github.com/WordPress/gutenberg/pull/67061
diff --git a/lib/class-wp-theme-json-gutenberg.php b/lib/class-wp-theme-json-gutenberg.php
index 10f80c3f3cdb7b..47301e4463e363 100644
--- a/lib/class-wp-theme-json-gutenberg.php
+++ b/lib/class-wp-theme-json-gutenberg.php
@@ -2874,8 +2874,14 @@ public function get_styles_for_block( $block_metadata ) {
 
 				// Combine selectors with style variation's selector and add to overall style variation declarations.
 				foreach ( $variation_declarations as $current_selector => $new_declarations ) {
-					// If current selector includes block classname, remove it but leave the whitespace in.
-					$shortened_selector = str_replace( $block_metadata['selector'] . ' ', ' ', $current_selector );
+					/*
+					 * Clean up any whitespace between comma separated selectors.
+					 * This prevents these spaces breaking compound selectors such as:
+					 * - `.wp-block-list:not(.wp-block-list .wp-block-list)`
+					 * - `.wp-block-image img, .wp-block-image.my-class img`
+					 */
+					$clean_current_selector = preg_replace( '/,\s+/', ',', $current_selector );
+					$shortened_selector     = str_replace( $block_metadata['selector'], '', $clean_current_selector );
 
 					// Prepend the variation selector to the current selector.
 					$split_selectors    = explode( ',', $shortened_selector );
diff --git a/phpunit/class-wp-theme-json-test.php b/phpunit/class-wp-theme-json-test.php
index 1aacb92759e591..c8ca89c7c1f6c7 100644
--- a/phpunit/class-wp-theme-json-test.php
+++ b/phpunit/class-wp-theme-json-test.php
@@ -4308,6 +4308,74 @@ public function data_get_styles_for_block_with_style_variations() {
 		);
 	}
 
+	public function test_get_styles_for_block_with_style_variations_and_custom_selectors() {
+		register_block_type(
+			'test/milk',
+			array(
+				'api_version' => 3,
+				'selectors'   => array(
+					'root'  => '.milk',
+					'color' => '.wp-block-test-milk .liquid, .wp-block-test-milk:not(.spoiled), .wp-block-test-milk.in-bottle',
+				),
+			)
+		);
+
+		register_block_style(
+			'test/milk',
+			array(
+				'name'  => 'chocolate',
+				'label' => 'Chocolate',
+			)
+		);
+
+		$theme_json = new WP_Theme_JSON_Gutenberg(
+			array(
+				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
+				'styles'  => array(
+					'blocks' => array(
+						'test/milk' => array(
+							'color'      => array(
+								'background' => 'white',
+							),
+							'variations' => array(
+								'chocolate' => array(
+									'color' => array(
+										'background' => '#35281E',
+									),
+								),
+							),
+						),
+					),
+				),
+			)
+		);
+
+		$metadata = array(
+			'name'       => 'test/milk',
+			'path'       => array( 'styles', 'blocks', 'test/milk' ),
+			'selector'   => '.wp-block-test-milk',
+			'selectors'  => array(
+				'color' => '.wp-block-test-milk .liquid, .wp-block-test-milk:not(.spoiled), .wp-block-test-milk.in-bottle',
+			),
+			'variations' => array(
+				'chocolate' => array(
+					'path'     => array( 'styles', 'blocks', 'test/milk', 'variations', 'chocolate' ),
+					'selector' => '.is-style-chocolate.wp-block-test-milk',
+				),
+			),
+		);
+
+		$actual_styles    = $theme_json->get_styles_for_block( $metadata );
+		$default_styles   = ':root :where(.wp-block-test-milk .liquid, .wp-block-test-milk:not(.spoiled), .wp-block-test-milk.in-bottle){background-color: white;}';
+		$variation_styles = ':root :where(.is-style-chocolate.wp-block-test-milk .liquid,.is-style-chocolate.wp-block-test-milk:not(.spoiled),.is-style-chocolate.wp-block-test-milk.in-bottle){background-color: #35281E;}';
+		$expected         = $default_styles . $variation_styles;
+
+		unregister_block_style( 'test/milk', 'chocolate' );
+		unregister_block_type( 'test/milk' );
+
+		$this->assertSame( $expected, $actual_styles );
+	}
+
 	public function test_block_style_variations() {
 		wp_set_current_user( static::$administrator_id );