diff --git a/boards/QUTy.json b/boards/QUTy.json
index 3b60e51..c862621 100644
--- a/boards/QUTy.json
+++ b/boards/QUTy.json
@@ -1,7 +1,7 @@
 {
   "build": {
     "extra_flags": "-D__AVR_DEV_LIB_NAME__=tn1626",
-    "f_cpu": "10000000L",
+    "f_cpu": "3333333L",
     "mcu": "attiny1626",
     "hwids": [
       [