diff --git a/avr/modules/flash/io_attn.asm b/avr/modules/flash/io_attn.asm
index 1332ff6..244c5a6 100644
--- a/avr/modules/flash/io_attn.asm
+++ b/avr/modules/flash/io_attn.asm
@@ -25,6 +25,7 @@
 ioWaitForAttnState100ms:
   cbi COM_ATTN_DDR, COM_ATTN_PIN          ; set ATTN port as input
   cbi COM_ATTN_OUTPUT, COM_ATTN_PIN       ; disable internal pullup for ATTN
+  nop
 ioWaitForAttnState100ms_loop:
 #ifdef LED_SIMPLE_PINNUM
     sbi LED_SIMPLE_PORTIN, LED_SIMPLE_PINNUM  ; toggle LED