diff --git a/modules/plugin/base/src/ns4xPlugin.cpp b/modules/plugin/base/src/ns4xPlugin.cpp
index 38f6210cb484..9d34d886aa39 100644
--- a/modules/plugin/base/src/ns4xPlugin.cpp
+++ b/modules/plugin/base/src/ns4xPlugin.cpp
@@ -48,7 +48,8 @@
 #include "nsIPluginStreamListener.h"
 #include "nsPluginsDir.h"
 #include "nsPluginSafety.h"
-#include "nsIPref.h"
+#include "nsIPrefService.h"
+#include "nsIPrefBranch.h"
 #include "nsPluginLogging.h"
 
 #include "nsIPluginInstancePeer2.h"
@@ -91,7 +92,6 @@ enum eNPPStreamTypeInternal {
 
 ////////////////////////////////////////////////////////////////////////
 // CID's && IID's
-static NS_DEFINE_CID(kPrefServiceCID, NS_PREF_CID);
 static NS_DEFINE_IID(kCPluginManagerCID, NS_PLUGINMANAGER_CID);
 static NS_DEFINE_IID(kPluginManagerCID, NS_PLUGINMANAGER_CID);
 static NS_DEFINE_IID(kMemoryCID, NS_MEMORY_CID);
@@ -1796,8 +1796,8 @@ _getvalue(NPP npp, NPNVariable variable, void *result)
 #endif
 
   case NPNVjavascriptEnabledBool: {
-    *(NPBool*)result = PR_FALSE; 
-    nsCOMPtr<nsIPref> prefs(do_GetService(kPrefServiceCID));
+    *(NPBool*)result = PR_FALSE;
+    nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID));
     if(prefs) {
       PRBool js = PR_FALSE;;
       res = prefs->GetBoolPref("javascript.enabled", &js);
diff --git a/modules/plugin/base/src/nsPluginDirServiceProvider.cpp b/modules/plugin/base/src/nsPluginDirServiceProvider.cpp
index 0e8edb6bb28b..71322711c1ac 100644
--- a/modules/plugin/base/src/nsPluginDirServiceProvider.cpp
+++ b/modules/plugin/base/src/nsPluginDirServiceProvider.cpp
@@ -40,7 +40,8 @@
 
 #include "nsCRT.h"
 #include "nsILocalFile.h"
-#include "nsIPref.h"
+#include "nsIPrefBranch.h"
+#include "nsIPrefService.h"
 #include "nsDependentString.h"
 #include "nsXPIDLString.h"
 #include "prmem.h"
@@ -214,7 +215,7 @@ nsPluginDirServiceProvider::GetFile(const char *prop, PRBool *persistant, nsIFil
   *persistant = PR_TRUE;
 
 #if defined(XP_WIN)    
-  nsCOMPtr<nsIPref> prefs = do_GetService(NS_PREF_CONTRACTID);
+  nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID))
   if (!prefs) return rv;
 
   if (nsCRT::strcmp(prop, NS_WIN_4DOTX_SCAN_KEY) == 0) {
diff --git a/modules/plugin/base/src/nsPluginsDirUnix.cpp b/modules/plugin/base/src/nsPluginsDirUnix.cpp
index 86f804a7c85d..a52a46bff6db 100644
--- a/modules/plugin/base/src/nsPluginsDirUnix.cpp
+++ b/modules/plugin/base/src/nsPluginsDirUnix.cpp
@@ -58,8 +58,8 @@
 #include <sys/stat.h>
 #include "nsString.h"
 #include "nsILocalFile.h"
-#include "nsIPref.h"
-static NS_DEFINE_CID(kPrefServiceCID, NS_PREF_CID);
+#include "nsIPrefBranch.h"
+#include "nsIPrefService.h"
 
 #define LOCAL_PLUGIN_DLL_SUFFIX ".so"
 #if defined(__hpux)
@@ -156,12 +156,12 @@ static void LoadExtraSharedLibs()
 {
     // check out if user's prefs.js has libs name
     nsresult res;
-    nsCOMPtr<nsIPref> prefs = do_GetService(kPrefServiceCID, &res);
+    nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &res));
     if (NS_SUCCEEDED(res) && (prefs != nsnull)) {
         char *sonamesListFromPref = PREF_PLUGINS_SONAME;
         char *sonameList = NULL;
         PRBool prefSonameListIsSet = PR_TRUE;
-        res = prefs->CopyCharPref(sonamesListFromPref, &sonameList);
+        res = prefs->GetCharPref(sonamesListFromPref, &sonameList);
         if (!sonameList) {
             // pref is not set, lets use hardcoded list
             prefSonameListIsSet = PR_FALSE;