diff --git a/floating_block.js b/floating_block.js
index 7103d87..db1a2bc 100644
--- a/floating_block.js
+++ b/floating_block.js
@@ -145,6 +145,7 @@ Drupal.blockFloatTracker = function (blockInfo) {
       position: 'fixed',
       top: topPosition + 'px',
     });
+    block.addClass('floating-fixed');
 
     blockInfo.floating = true;
   }
@@ -164,6 +165,7 @@ Drupal.blockFloatResetPosition = function (block, blockInfo) {
       position: blockInfo.original_css.position,
       top: blockInfo.original_css.top
     });
+    block.removeClass('floating-fixed');
     blockInfo.floating = false;
   }
 }