diff --git a/modules/plugin/src/npglue.h b/modules/plugin/src/npglue.h
index 58e4b4d20145..0b528f13c659 100644
--- a/modules/plugin/src/npglue.h
+++ b/modules/plugin/src/npglue.h
@@ -282,8 +282,7 @@ npn_SetWindowSize(np_instance* instance, NPSize* pnpsz);
 
 ////////////////////////////////////////////////////////////////////////////////
 
-class nsPluginManager : public nsIPluginManager2,
-                        public nsINetworkManager
+class nsPluginManager : public nsIPluginManager2
 {
 public: