diff --git a/lib/renderer.js b/lib/renderer.js
index 768c8bb..e74367a 100644
--- a/lib/renderer.js
+++ b/lib/renderer.js
@@ -20,10 +20,11 @@ function pandocProcess(pandocPath, args, timeout, filePath, input) {
     return result.stdout;
   }
   if (result.error) {
-    printMessage('ERROR', filePath, result.error);
+    printMessage('ERROR', filePath, result.error.toString());
     throw result.error;
   }
-  printMessage('ERROR', filePath, 'pandoc exited with code ' + result.status + (result.stderr ? ': ' + result.stderr : '.'));
+  const error_msg = 'pandoc exited with code ' + result.status + (result.stderr ? ': ' + result.stderr : '.');
+  printMessage('ERROR', filePath, error_msg);
   throw Error(error_msg);
 }