diff --git a/security/manager/pki/resources/content/certManager.js b/security/manager/pki/resources/content/certManager.js
index b2cce70c7ae6..56060c781bb4 100644
--- a/security/manager/pki/resources/content/certManager.js
+++ b/security/manager/pki/resources/content/certManager.js
@@ -315,7 +315,7 @@ function deleteCerts()
 {
   getSelectedCerts();
   
-  var params = Components.classes[nsDialogParamBlock].getService(nsIDialogParamBlock);
+  var params = Components.classes[nsDialogParamBlock].createInstance(nsIDialogParamBlock);
   
   var bundle = srGetStrBundle("chrome://pippki/locale/pippki.properties");
   var selTab = document.getElementById('certMgrTabbox').selectedItem;
diff --git a/security/manager/pki/resources/content/pref-masterpass.js b/security/manager/pki/resources/content/pref-masterpass.js
index 3b1ac5b11218..399130e27cd6 100644
--- a/security/manager/pki/resources/content/pref-masterpass.js
+++ b/security/manager/pki/resources/content/pref-masterpass.js
@@ -100,7 +100,7 @@ function changePasswordSettings()
 
 function ChangePW()
 {
-  var params = Components.classes[nsDialogParamBlock].getService(nsIDialogParamBlock);
+  var params = Components.classes[nsDialogParamBlock].createInstance(nsIDialogParamBlock);
   params.SetString(1,"_blank");
   window.openDialog("chrome://pippki/content/changepassword.xul","",
               "chrome,resizable=1,modal=1,dialog=1",params);