diff --git a/toolkit/components/url-classifier/nsUrlClassifierDBService.h b/toolkit/components/url-classifier/nsUrlClassifierDBService.h
index 79ddb9232311..7517e8c6f061 100644
--- a/toolkit/components/url-classifier/nsUrlClassifierDBService.h
+++ b/toolkit/components/url-classifier/nsUrlClassifierDBService.h
@@ -93,10 +93,6 @@ private:
   // uris on document loads.
   bool mCheckPhishing;
 
-  // TRUE if we randomize the prefixes/domains per client to prevent
-  // simulatenous collisions for all Firefox users
-  bool mPerClientRandomize;
-
   // TRUE if a BeginUpdate() has been called without an accompanying
   // CancelUpdate()/FinishUpdate().  This is used to prevent competing
   // updates, not to determine whether an update is still being