diff --git a/packages/php/email-editor/src/Engine/Renderer/ContentRenderer/class-content-renderer.php b/packages/php/email-editor/src/Engine/Renderer/ContentRenderer/class-content-renderer.php
index 0b54536ed7..6c0193bf13 100644
--- a/packages/php/email-editor/src/Engine/Renderer/ContentRenderer/class-content-renderer.php
+++ b/packages/php/email-editor/src/Engine/Renderer/ContentRenderer/class-content-renderer.php
@@ -131,13 +131,14 @@ class Content_Renderer {
 	}
 
 	/**
-	 * Render block
+	 * Renders block
+	 * Translates block's HTML to HTML suitable for email clients. The method is intended as a callback for 'render_block' filter.
 	 *
 	 * @param string $block_content Block content.
 	 * @param array  $parsed_block Parsed block.
 	 * @return string
 	 */
-	public function render_block( $block_content, $parsed_block ) {
+	public function render_block( string $block_content, array $parsed_block ): string {
 		$renderer = $this->blocks_registry->get_block_renderer( $parsed_block['blockName'] );
 		if ( ! $renderer ) {
 			$renderer = $this->blocks_registry->get_fallback_renderer();
@@ -213,7 +214,7 @@ class Content_Renderer {
 		);
 
 		/*
-		 *Layout CSS assumes the top level block will have a single DIV wrapper with children. Since our blocks use tables,
+		 * Layout CSS assumes the top level block will have a single DIV wrapper with children. Since our blocks use tables,
 		 * we need to adjust this to look for children in the TD element. This may requires more advanced replacement but
 		 * this works in the current version of Gutenberg.
 		 * Example rule we're targetting: .wp-container-core-group-is-layout-1.wp-container-core-group-is-layout-1 > *
diff --git a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php
index 7211dd4a0a..7f23446c24 100644
--- a/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php
+++ b/packages/php/email-editor/tests/integration/Engine/Renderer/ContentRenderer/Content_Renderer_Test.php
@@ -72,6 +72,60 @@ class Content_Renderer_Test extends \MailPoetTest {
 		verify( $paragraph_styles )->stringContainsString( 'display: block' );
 	}
 
+	/**
+	 * Test It Renders Block With Fallback Renderer
+	 */
+	public function testItRendersBlockWithFallbackRenderer(): void {
+		$fallback_renderer = $this->createMock( Block_Renderer::class );
+		$fallback_renderer->expects( $this->once() )->method( 'render' );
+		$blocks_registry = $this->createMock( Blocks_Registry::class );
+		$blocks_registry->expects( $this->once() )->method( 'get_block_renderer' )->willReturn( null );
+		$blocks_registry->expects( $this->once() )->method( 'get_fallback_renderer' )->willReturn( $fallback_renderer );
+		$renderer = $this->getServiceWithOverrides(
+			Content_Renderer::class,
+			array(
+				'blocks_registry' => $blocks_registry,
+			)
+		);
+
+		$renderer->render_block( 'content', array( 'blockName' => 'block' ) );
+	}
+
+	/**
+	 * Test It Renders Block With Block Renderer
+	 */
+	public function testItRendersBlockWithBlockRenderer(): void {
+		$renderer        = $this->createMock( Block_Renderer::class );
+		$blocks_registry = $this->createMock( Blocks_Registry::class );
+		$blocks_registry->expects( $this->once() )->method( 'get_block_renderer' )->willReturn( $renderer );
+		$blocks_registry->expects( $this->never() )->method( 'get_fallback_renderer' )->willReturn( null );
+		$renderer = $this->getServiceWithOverrides(
+			Content_Renderer::class,
+			array(
+				'blocks_registry' => $blocks_registry,
+			)
+		);
+
+		$renderer->render_block( 'content', array( 'blockName' => 'block' ) );
+	}
+
+	/**
+	 * Test It Renders Block When no Renderer available
+	 */
+	public function testItReturnsContentIfNoRendererAvailable(): void {
+		$blocks_registry = $this->createMock( Blocks_Registry::class );
+		$blocks_registry->expects( $this->once() )->method( 'get_block_renderer' )->willReturn( null );
+		$blocks_registry->expects( $this->once() )->method( 'get_fallback_renderer' )->willReturn( null );
+		$renderer = $this->getServiceWithOverrides(
+			Content_Renderer::class,
+			array(
+				'blocks_registry' => $blocks_registry,
+			)
+		);
+
+		verify( $renderer->render_block( 'content', array( 'blockName' => 'block' ) ) )->equals( 'content' );
+	}
+
 	/**
 	 * Get the value of the style attribute for a given tag in the HTML.
 	 *