diff --git a/cmd/imageproxy/main.go b/cmd/imageproxy/main.go
index 77ae035..9d3bcd9 100644
--- a/cmd/imageproxy/main.go
+++ b/cmd/imageproxy/main.go
@@ -62,7 +62,7 @@ func main() {
 			CacheSizeMax: *cacheSize * 1024 * 1024,
 		})
 		c = diskcache.NewWithDiskv(d)
-	} else {
+	} else if *cacheSize != 0 {
 		c = httpcache.NewMemoryCache()
 	}