diff --git a/calendar/providers/caldav/calDavCalendar.js b/calendar/providers/caldav/calDavCalendar.js
index 715b7e9dea9..e8bec16451a 100644
--- a/calendar/providers/caldav/calDavCalendar.js
+++ b/calendar/providers/caldav/calDavCalendar.js
@@ -1052,7 +1052,7 @@ WebDavResource.prototype = {
             return this;
         }
        
-        throw Components.interfaces.NS_NO_INTERFACE;
+        throw Components.interfaces.NS_ERROR_NO_INTERFACE;
     }
 };
 
diff --git a/calendar/providers/ics/calICSCalendar.js b/calendar/providers/ics/calICSCalendar.js
index 3178bbc33e9..b8fbfe1033c 100644
--- a/calendar/providers/ics/calICSCalendar.js
+++ b/calendar/providers/ics/calICSCalendar.js
@@ -924,7 +924,7 @@ WebDavResource.prototype = {
             iid.equals(CI.nsISupports)) {
             return this;
         }
-        throw Components.interfaces.NS_NO_INTERFACE;
+        throw Components.interfaces.NS_ERROR_NO_INTERFACE;
     }
 };
 
diff --git a/extensions/webdav/tests/davshell.js b/extensions/webdav/tests/davshell.js
index 453ac8d3f76..e377efc61bd 100644
--- a/extensions/webdav/tests/davshell.js
+++ b/extensions/webdav/tests/davshell.js
@@ -85,7 +85,7 @@ Resource.prototype = {
            return this;
        }
        
-       throw Components.interfaces.NS_NO_INTERFACE;
+       throw Components.interfaces.NS_ERROR_NO_INTERFACE;
    }
 };