diff --git a/js/affix.js b/js/affix.js
index deea29485f..04f389e2c5 100644
--- a/js/affix.js
+++ b/js/affix.js
@@ -53,7 +53,7 @@
     var colliderTop    = initializing ? scrollTop : position.top
     var colliderHeight = initializing ? targetHeight : height
 
-    if (offsetTop != null && colliderTop <= offsetTop) return 'top'
+    if (offsetTop != null && scrollTop <= offsetTop) return 'top'
     if (offsetBottom != null && (colliderTop + colliderHeight >= scrollHeight - offsetBottom)) return 'bottom'
 
     return false