diff --git a/control.go b/control.go
index ada72697..14b1506a 100644
--- a/control.go
+++ b/control.go
@@ -569,7 +569,7 @@ func handleFilteringAddURL(w http.ResponseWriter, r *http.Request) {
 	f.Enabled = true
 
 	// Download the filter contents
-	ok, err := f.update(true)
+	ok, err := f.update()
 	if err != nil {
 		httpError(w, http.StatusBadRequest, "Couldn't fetch filter from url %s: %s", f.URL, err)
 		return
diff --git a/filter.go b/filter.go
index c294b3b5..45115414 100644
--- a/filter.go
+++ b/filter.go
@@ -179,7 +179,11 @@ func refreshFiltersIfNecessary(force bool) int {
 			continue
 		}
 
-		updated, err := filter.update(force)
+		if !force && time.Since(filter.LastUpdated) <= updatePeriod {
+			continue
+		}
+
+		updated, err := filter.update()
 		if err != nil {
 			log.Printf("Failed to update filter %s: %s\n", filter.URL, err)
 			continue
@@ -193,6 +197,11 @@ func refreshFiltersIfNecessary(force bool) int {
 			}
 
 			updateCount++
+
+		} else {
+			mtime := time.Now()
+			os.Chtimes(filter.Path(), mtime, mtime)
+			filter.LastUpdated = mtime
 		}
 	}
 	config.Unlock()
@@ -236,14 +245,8 @@ func parseFilterContents(contents []byte) (int, string, []string) {
 	return rulesCount, name, lines
 }
 
-// Checks for filters updates
-// If "force" is true -- does not check the filter's LastUpdated field
-// Call "save" to persist the filter contents
-func (filter *filter) update(force bool) (bool, error) {
-	if !force && time.Since(filter.LastUpdated) <= updatePeriod {
-		return false, nil
-	}
-
+// Perform upgrade on a filter
+func (filter *filter) update() (bool, error) {
 	log.Tracef("Downloading update for filter %d from %s", filter.ID, filter.URL)
 
 	resp, err := client.Get(filter.URL)