diff --git a/src/wp-includes/class-wp-block-styles-registry.php b/src/wp-includes/class-wp-block-styles-registry.php
index 67d6998fc5..272e400f8c 100644
--- a/src/wp-includes/class-wp-block-styles-registry.php
+++ b/src/wp-includes/class-wp-block-styles-registry.php
@@ -62,6 +62,15 @@ final class WP_Block_Styles_Registry {
 			return false;
 		}
 
+		if ( str_contains( $style_properties['name'], ' ' ) ) {
+			_doing_it_wrong(
+				__METHOD__,
+				__( 'Block style name must not contain any spaces.' ),
+				'5.9.0'
+			);
+			return false;
+		}
+
 		$block_style_name = $style_properties['name'];
 
 		if ( ! isset( $this->registered_block_styles[ $block_name ] ) ) {
diff --git a/tests/phpunit/tests/blocks/register.php b/tests/phpunit/tests/blocks/register.php
index 18463671d4..b9efb5ee68 100644
--- a/tests/phpunit/tests/blocks/register.php
+++ b/tests/phpunit/tests/blocks/register.php
@@ -8,7 +8,7 @@
  */
 
 /**
- * Tests for register_block_type(), unregister_block_type(), get_dynamic_block_names().
+ * Tests for register_block_type(), unregister_block_type(), get_dynamic_block_names() and register_block_style().
  *
  * @since 5.0.0
  *
@@ -559,4 +559,61 @@ class Tests_Blocks_Register extends WP_UnitTestCase {
 
 		$this->assertSame( 3, $result->api_version );
 	}
+
+	/**
+	 * Test case to validate `_doing_it_wrong()` when block style name attribute
+	 * contains one or more spaces.
+	 *
+	 * @dataProvider data_register_block_style_name_contain_spaces
+	 *
+	 * @ticket 54296
+	 *
+	 * @covers ::register_block_style
+	 *
+	 * @expectedIncorrectUsage WP_Block_Styles_Registry::register
+	 * @param array $block_styles Array of block styles to test.
+	 */
+	public function test_register_block_style_name_contain_spaces( array $block_styles ) {
+		register_block_style( 'core/query', $block_styles );
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array
+	 */
+	public function data_register_block_style_name_contain_spaces() {
+		return array(
+			'multiple spaces' => array(
+				array(
+					'name'  => 'style-class-1    style-class-2',
+					'label' => 'Custom Style Label',
+				),
+			),
+			'single space'    => array(
+				array(
+					'name'  => 'style-class-1 style-class-2',
+					'label' => 'Custom Style Label',
+				),
+			),
+		);
+	}
+
+	/**
+	 * Test case to validate no `_doing_it_wrong()` happens when there is
+	 * no empty space.
+	 *
+	 * @ticket 54296
+	 *
+	 * @covers ::register_block_style
+	 */
+	public function test_register_block_style_name_without_spaces() {
+		$block_styles = array(
+			'name'  => 'style-class-1',
+			'label' => 'Custom Style Label',
+		);
+
+		$actual = register_block_style( 'core/query', $block_styles );
+		$this->assertTrue( $actual );
+	}
 }