diff --git a/avr/common/m_ringbuffer_y.asm b/avr/common/m_ringbuffer_y.asm
index 31ca3c3..8c32e50 100644
--- a/avr/common/m_ringbuffer_y.asm
+++ b/avr/common/m_ringbuffer_y.asm
@@ -111,8 +111,6 @@ l_end:
   tst r17
   clc
   breq l_end
-  dec r17
-  std Y+@1, r17 ; usedBytes
   ldd r17, Y+@2 ; readPos
   mov xl, yl
   mov xh, yh