diff --git a/go/ckit/cache/cache.go b/go/ckit/cache/cache.go
index ed6c9c6..8c3c8e0 100644
--- a/go/ckit/cache/cache.go
+++ b/go/ckit/cache/cache.go
@@ -86,16 +86,18 @@ func (c *Cache) startSizeWatcher() {
 		for t := range ticker.C {
 			fi, err := os.Stat(c.Path)
 			if err != nil {
-				log.Printf("could not stat file at %s, stopping watch thread", c.Path)
+				log.Printf("[cache] could not stat file at %s", c.Path)
 				break
 			}
 			if fi.Size() > c.MaxFileSize {
 				c.Lock()
-				log.Printf("switching cache at %s to read-only mode at %v", c.Path, t)
+				log.Printf("[cache] switching %s to read-only mode at %v", c.Path, t.Format(time.RFC3339))
 				c.readOnly = true
 				c.Unlock()
+				break
 			}
 		}
+		log.Printf("[cache] stopping file watcher thread")
 	}()
 }
 
diff --git a/go/ckit/cmd/labed/main.go b/go/ckit/cmd/labed/main.go
index 5e079eb..59a33f7 100644
--- a/go/ckit/cmd/labed/main.go
+++ b/go/ckit/cmd/labed/main.go
@@ -40,6 +40,7 @@ var (
 	enableGzip             = flag.Bool("z", false, "enable gzip compression")
 	enableCache            = flag.Bool("c", false, "enable caching of expensive responses")
 	cacheTriggerDuration   = flag.Duration("t", 250*time.Millisecond, "cache trigger duration")
+	cacheMaxFileSize       = flag.Int64("cx", 1<<36, "maximum filesize cache in bytes")
 	showVersion            = flag.Bool("version", false, "show version")
 	accessLogFile          = flag.String("a", "", "path to access log file, do not write access log if empty")
 	logFile                = flag.String("logfile", "", "application log file (stderr if empty)")
@@ -200,6 +201,7 @@ func main() {
 			log.Fatal(err)
 		}
 		defer c.Close()
+		c.MaxFileSize = *cacheMaxFileSize
 		srv.Cache = c
 		srv.CacheTriggerDuration = *cacheTriggerDuration
 	}