diff --git a/modules/plugin/base/public/nsIClassicPluginFactory.h b/modules/plugin/base/public/nsIClassicPluginFactory.h
new file mode 100644
index 000000000000..f86e6b015302
--- /dev/null
+++ b/modules/plugin/base/public/nsIClassicPluginFactory.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s): 
+ */
+
+#ifndef nsIClassicPluginFactory_h___
+#define nsIClassicPluginFactory_h___
+
+#include "nsplugindefs.h"
+#include "nsISupports.h"
+
+// {07bfa284-1dd2-11b2-90f8-fef5608e8a56}
+#define NS_ICLASSICPLUGINFACTORY_IID \
+{ 0x07bfa284, 0x1dd2, 0x11b2, { 0x90, 0xf8, 0xfe, 0xf5, 0x60, 0x8e, 0x8a, 0x56 } }
+
+// {a55d21ca-1dd1-11b2-9b0f-8fe1adaf129d}
+#define NS_CLASSIC_PLUGIN_FACTORY_CID \
+{ 0xa55d21ca, 0x1dd1, 0x11b2, { 0x9b, 0x0f, 0x8f, 0xe1, 0xad, 0xaf, 0x12, 0x9d } }
+
+// Prefix for ContractID of all plugins
+#define NS_CLASSIC_PLUGIN_FACTORY_CONTRACTID "@mozilla.org/plugin/classicpluginfactory;1"
+
+struct PRLibrary;
+
+class nsIClassicPluginFactory : public nsISupports {
+public:
+	NS_DEFINE_STATIC_IID_ACCESSOR(NS_ICLASSICPLUGINFACTORY_IID)
+
+   /**
+    * A factory method for constructing 4.x plugins. Constructs
+    * and initializes an ns4xPlugin object, and returns it in
+    * <b>result</b>.
+    */
+    NS_IMETHOD CreatePlugin(nsIServiceManager* aServiceMgr, const char* aFileName,
+                            PRLibrary* aLibrary, nsIPlugin** aResult) = 0;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif /* nsIClassicPluginFactory_h___ */
diff --git a/modules/plugin/public/nsIClassicPluginFactory.h b/modules/plugin/public/nsIClassicPluginFactory.h
new file mode 100644
index 000000000000..f86e6b015302
--- /dev/null
+++ b/modules/plugin/public/nsIClassicPluginFactory.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * The contents of this file are subject to the Netscape Public
+ * License Version 1.1 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS
+ * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * rights and limitations under the License.
+ *
+ * The Original Code is mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is Netscape
+ * Communications Corporation.  Portions created by Netscape are
+ * Copyright (C) 1998 Netscape Communications Corporation. All
+ * Rights Reserved.
+ *
+ * Contributor(s): 
+ */
+
+#ifndef nsIClassicPluginFactory_h___
+#define nsIClassicPluginFactory_h___
+
+#include "nsplugindefs.h"
+#include "nsISupports.h"
+
+// {07bfa284-1dd2-11b2-90f8-fef5608e8a56}
+#define NS_ICLASSICPLUGINFACTORY_IID \
+{ 0x07bfa284, 0x1dd2, 0x11b2, { 0x90, 0xf8, 0xfe, 0xf5, 0x60, 0x8e, 0x8a, 0x56 } }
+
+// {a55d21ca-1dd1-11b2-9b0f-8fe1adaf129d}
+#define NS_CLASSIC_PLUGIN_FACTORY_CID \
+{ 0xa55d21ca, 0x1dd1, 0x11b2, { 0x9b, 0x0f, 0x8f, 0xe1, 0xad, 0xaf, 0x12, 0x9d } }
+
+// Prefix for ContractID of all plugins
+#define NS_CLASSIC_PLUGIN_FACTORY_CONTRACTID "@mozilla.org/plugin/classicpluginfactory;1"
+
+struct PRLibrary;
+
+class nsIClassicPluginFactory : public nsISupports {
+public:
+	NS_DEFINE_STATIC_IID_ACCESSOR(NS_ICLASSICPLUGINFACTORY_IID)
+
+   /**
+    * A factory method for constructing 4.x plugins. Constructs
+    * and initializes an ns4xPlugin object, and returns it in
+    * <b>result</b>.
+    */
+    NS_IMETHOD CreatePlugin(nsIServiceManager* aServiceMgr, const char* aFileName,
+                            PRLibrary* aLibrary, nsIPlugin** aResult) = 0;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif /* nsIClassicPluginFactory_h___ */