diff --git a/test/sanity/validate-modules/validate-modules b/test/sanity/validate-modules/validate-modules
index b794b0d9c4..6b626f55e4 100755
--- a/test/sanity/validate-modules/validate-modules
+++ b/test/sanity/validate-modules/validate-modules
@@ -428,9 +428,15 @@ class ModuleValidator(Validator):
 
         for error in errors:
             path = [str(p) for p in error.path]
+
+            if isinstance(error.data, dict):
+                error_message = humanize_error(error.data, error)
+            else:
+                error_message = error
+
             self.errors.append('%s.%s: %s' %
                                (name, '.'.join(path),
-                                humanize_error(error.data, error)))
+                                error_message))
 
     def _validate_docs(self):
         doc_info = self._get_docs()