diff --git a/projects/packages/jetpack-mu-wpcom/changelog/fix-verbum-block-test-wp-trunk b/projects/packages/jetpack-mu-wpcom/changelog/fix-verbum-block-test-wp-trunk
new file mode 100644
index 000000000000..0cdb2aab3e43
--- /dev/null
+++ b/projects/packages/jetpack-mu-wpcom/changelog/fix-verbum-block-test-wp-trunk
@@ -0,0 +1,3 @@
+Significance: patch
+Type: changed
+Comment: Update Verbum block test expectations for WordPress 7.0+ block output changes.
diff --git a/projects/packages/jetpack-mu-wpcom/tests/php/features/verbum-comments/Verbum_Block_Utils_Test.php b/projects/packages/jetpack-mu-wpcom/tests/php/features/verbum-comments/Verbum_Block_Utils_Test.php
index 7e052d482cd1..12b15194a014 100644
--- a/projects/packages/jetpack-mu-wpcom/tests/php/features/verbum-comments/Verbum_Block_Utils_Test.php
+++ b/projects/packages/jetpack-mu-wpcom/tests/php/features/verbum-comments/Verbum_Block_Utils_Test.php
@@ -8,7 +8,9 @@
 use Automattic\Jetpack\Jetpack_Mu_Wpcom;
 use Brain\Monkey\Functions;
 use PHPUnit\Framework\Attributes\CoversClass;
+
 require_once Jetpack_Mu_Wpcom::PKG_DIR . 'src/features/verbum-comments/assets/class-verbum-block-utils.php';
+require_once __DIR__ . '/../../trait-wp-version-test-helpers.php';
 
 /**
  * Test class for Verbum_Block_Utils.
@@ -17,6 +19,8 @@
  */
 #[CoversClass( Verbum_Block_Utils::class )]
 class Verbum_Block_Utils_Test extends \WorDBless\BaseTestCase {
+	use Jetpack_Mu_Wpcom_WP_Version_Test_Helpers;
+
 	/**
 	 * Ensure string comments are not modified when 'render_verbum_blocks' is applied
 	 */
@@ -43,7 +47,14 @@ public function test_comment_text_block_sanitization_sanity_check() {
 		$comment_content  = '<!-- wp:paragraph --><p>test</p><!-- /wp:paragraph --><!-- wp:list --><ul><!-- wp:list-item --><li>1</li><!-- /wp:list-item --><!-- wp:list-item --><li>2</li><!-- /wp:list-item --><!-- wp:list-item --><li>3</li><!-- /wp:list-item --></ul><!-- /wp:list --><!-- wp:quote --><blockquote class="wp-block-quote"><!-- wp:paragraph --><p>something</p><!-- /wp:paragraph --><cite>someone</cite></blockquote><!-- /wp:quote -->';
 		$filtered_content = preg_replace( '/\R+/', '', Verbum_Block_Utils::render_verbum_blocks( $comment_content ) );
 
-		$expected_content = '<p>test</p><ul><li>1</li><li>2</li><li>3</li></ul><blockquote class="wp-block-quote is-layout-flow wp-block-quote-is-layout-flow"><p>something</p><cite>someone</cite></blockquote>';
+		// WordPress trunk (7.0+) removed layout classes from block output (Gutenberg PR #71207).
+		// We need to handle both old (with classes) and new (without classes) formats.
+		// @todo Simplify to a single expected value once WP 7.0 is the minimum supported version.
+		$expected_content_wp7 = '<p>test</p><ul><li>1</li><li>2</li><li>3</li></ul><blockquote class="wp-block-quote"><p>something</p><cite>someone</cite></blockquote>';
+		$expected_content_wp6 = '<p>test</p><ul><li>1</li><li>2</li><li>3</li></ul><blockquote class="wp-block-quote is-layout-flow wp-block-quote-is-layout-flow"><p>something</p><cite>someone</cite></blockquote>';
+
+		$expected_content = $this->get_version_specific_expected_html( $expected_content_wp7, $expected_content_wp6 );
+
 		$this->assertSame( $expected_content, $filtered_content );
 	}
 
diff --git a/projects/packages/jetpack-mu-wpcom/tests/php/trait-wp-version-test-helpers.php b/projects/packages/jetpack-mu-wpcom/tests/php/trait-wp-version-test-helpers.php
new file mode 100644
index 000000000000..2beddaee3c55
--- /dev/null
+++ b/projects/packages/jetpack-mu-wpcom/tests/php/trait-wp-version-test-helpers.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Trait for handling WordPress version-specific test expectations.
+ *
+ * WordPress trunk (7.0+) changed block output in Gutenberg PR #71207,
+ * removing layout classes like 'is-layout-flow' and 'wp-block-quote-is-layout-flow'.
+ *
+ * This trait provides helper methods to handle version-specific expectations in tests.
+ *
+ * @todo Remove this trait once WP 7.0 is the minimum supported version.
+ *
+ * @package automattic/jetpack-mu-wpcom
+ */
+
+trait Jetpack_Mu_Wpcom_WP_Version_Test_Helpers {
+
+	/**
+	 * Determine if we're testing against WordPress 7.0+ (trunk).
+	 *
+	 * WordPress 7.0+ removed layout classes from block output (Gutenberg PR #71207).
+	 *
+	 * @return bool True if WordPress 7.0+, false otherwise.
+	 */
+	protected function is_wp_7_or_higher() {
+		global $wp_version;
+
+		if ( empty( $wp_version ) ) {
+			return false;
+		}
+
+		return version_compare( $wp_version, '7.0-dev', '>=' );
+	}
+
+	/**
+	 * Get version-appropriate expected HTML for block output.
+	 *
+	 * @param string $html_without_layout_classes HTML without layout classes (WP 7.0+ format).
+	 * @param string $html_with_layout_classes HTML with layout classes (WP 6.9 and earlier format).
+	 * @return string The appropriate HTML for the current WordPress version.
+	 */
+	protected function get_version_specific_expected_html( $html_without_layout_classes, $html_with_layout_classes ) {
+		if ( $this->is_wp_7_or_higher() ) {
+			return $html_without_layout_classes;
+		}
+
+		return $html_with_layout_classes;
+	}
+}
diff --git a/projects/plugins/jetpack/changelog/fix-block-tests-wp-version b/projects/plugins/jetpack/changelog/fix-block-tests-wp-version
new file mode 100644
index 000000000000..40443d5bd314
--- /dev/null
+++ b/projects/plugins/jetpack/changelog/fix-block-tests-wp-version
@@ -0,0 +1,3 @@
+Significance: patch
+Type: other
+Comment: Normalize block fixture test output for WordPress version compatibility.
diff --git a/projects/plugins/jetpack/tests/php/extensions/blocks/class-block-fixture-testcase.php b/projects/plugins/jetpack/tests/php/extensions/blocks/class-block-fixture-testcase.php
index f172e6101cd0..164c879b3f8d 100644
--- a/projects/plugins/jetpack/tests/php/extensions/blocks/class-block-fixture-testcase.php
+++ b/projects/plugins/jetpack/tests/php/extensions/blocks/class-block-fixture-testcase.php
@@ -39,11 +39,14 @@ public function generate_server_side_rendering_based_on_serialized_fixtures(
 			$parsed_blocks   = parse_blocks( $block_markup );
 			$rendered_output = trim( render_block( $parsed_blocks[0] ) );
 
+			// Normalize output for version-agnostic comparison
+			$normalized_output = $this->normalize_block_output( $rendered_output );
+
 			$target_markup_filename = str_replace( '.serialized.html', $target_extension, $file );
 
 			// Create a server rendered fixture if one does not exist.
 			if ( ! file_exists( $target_markup_filename ) ) {
-				file_put_contents( $target_markup_filename, $rendered_output );
+				file_put_contents( $target_markup_filename, $normalized_output );
 				$fail_messages[] =
 					sprintf(
 						"No server rendered fixture could be found for the %s block's %s fixture\n" .
@@ -56,8 +59,8 @@ public function generate_server_side_rendering_based_on_serialized_fixtures(
 
 			$server_rendered_fixture = file_get_contents( $target_markup_filename );
 			$this->assertEquals(
-				$rendered_output,
-				trim( $server_rendered_fixture ),
+				$normalized_output,
+				$this->normalize_block_output( trim( $server_rendered_fixture ) ),
 				sprintf(
 					'The results of render_block for %s called with serialized markup from %s do not match ' .
 					"the server-rendered fixture: %s\n",
@@ -76,4 +79,35 @@ public function generate_server_side_rendering_based_on_serialized_fixtures(
 			);
 		}
 	}
+
+	/**
+	 * Normalize block HTML output for version-agnostic comparison.
+	 *
+	 * Strips classes that vary between WordPress versions so fixtures work
+	 * on both WP latest and WP trunk:
+	 * - `is-layout-*` classes (removed in WP trunk, Gutenberg PR #71207)
+	 * - `wp-block-*-is-layout-*` classes (same change)
+	 * - `wp-block-paragraph` class (added in WP trunk, core r61605)
+	 * - Leftover empty `class=""` attributes after stripping
+	 *
+	 * @todo Remove this method once WP 7.0 is the minimum supported version.
+	 *
+	 * @param string $html The HTML content to normalize.
+	 * @return string The normalized HTML.
+	 */
+	private function normalize_block_output( $html ) {
+		// Remove wp-block-*-is-layout-* classes (must come before is-layout-* to avoid partial matches).
+		$html = preg_replace( '/\s*wp-block-[a-z-]+-is-layout-[a-z-]+/', '', $html );
+
+		// Remove is-layout-* classes.
+		$html = preg_replace( '/\s*is-layout-[a-z-]+/', '', $html );
+
+		// Remove wp-block-paragraph class.
+		$html = preg_replace( '/\s*wp-block-paragraph/', '', $html );
+
+		// Remove leftover empty class attributes.
+		$html = preg_replace( '/\s*class=""/', '', $html );
+
+		return $html;
+	}
 }