diff --git a/block_class.module b/block_class.module
index 9dc7386..869dbe6 100644
--- a/block_class.module
+++ b/block_class.module
@@ -37,6 +37,10 @@ function block_class_preprocess_block(&$vars) {
     $classes = $_block_class_blocks_classes[$block->module][$block->delta];
     $vars['classes_array'] = array_merge($vars['classes_array'], explode(' ', $classes));
   }
+
+  if (!empty($block->classes)) {
+    $vars['classes_array'] = array_merge($vars['classes_array'], $block->classes);
+  }
 }