diff --git a/sphinx/domains/javascript.py b/sphinx/domains/javascript.py
index 9698c3d07..d04c101d6 100644
--- a/sphinx/domains/javascript.py
+++ b/sphinx/domains/javascript.py
@@ -56,7 +56,8 @@ class JSObject(ObjectDescription):
         signode['object'] = objectname
         signode['fullname'] = fullname
 
-        signode += addnodes.desc_addname(nameprefix, nameprefix)
+        if nameprefix:
+            signode += addnodes.desc_addname(nameprefix, nameprefix)
         signode += addnodes.desc_name(name, name)
         if self.has_arguments:
             signode += addnodes.desc_parameterlist()