diff --git a/src/main.ts b/src/main.ts
index 0af0054..56cd4cf 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -13,7 +13,7 @@ const height_ = 594
 const cellSize_ = 12
 const padding_ = 5 // * cellSize
 
-const randomSeed = () => Math.random().toString(2).split('.').pop()!.slice(Math.floor(Math.random() * -9))
+const randomSeed = () => [...range(Math.ceil(Math.random() * 10))].map(_ => Math.round(Math.random())).join('')
 
 const xSeeds_ = randomSeed()
 const ySeeds_ = randomSeed()