diff --git a/docker-compose.yml b/docker-compose.yml
index 9bb1ee6..36d7388 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -17,6 +17,8 @@ services:
       - /usr/src/app/node_modules
     links:
       - maildev
+    depends_on:
+      - maildev
     environment:
       - MAILDEV_SMTP_PORT=25
       - MAILDEV_SMTP_ENDPOINT=maildev
diff --git a/src/helpers/buildMjmlTemplate.ts b/src/helpers/buildMjmlTemplate.ts
index 6c5ce3d..26718f0 100644
--- a/src/helpers/buildMjmlTemplate.ts
+++ b/src/helpers/buildMjmlTemplate.ts
@@ -26,13 +26,14 @@ export const buildMjmlTemplate = async (options: IPluginOptions, templateName: s
         throw new Error(`[nodemailer-mjml] - Could not read mjml template at path: ${mjmlTemplatePath}`);
     });
 
-    const shouldRunMustacheCompiler = !!templateData && Object.keys(templateData).length > 0;
+    const shouldRunMustacheCompiler = !!templateData && Object.keys(templateData ?? {}).length > 0;
     const mustacheRenderedTemplate = shouldRunMustacheCompiler ? render(rawMjmlTemplate, templateData) : rawMjmlTemplate;
 
     const mjmlOutput = mjml2html(mustacheRenderedTemplate, {
         filePath: mjmlTemplatePath,
         ...renderOptions.mjmlOptions
     });
+
     checkMjmlError(mjmlOutput);
 
     const finalHtmlOutput = renderOptions.minifyHtmlOutput ? minify(mjmlOutput.html, renderOptions.htmlMinifierOptions) : mjmlOutput.html;