diff --git a/README.md b/README.md
index 9af0b5c..ded4b68 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ make and break time of a relay.
 1. VDD(+5v)
 2. PA4(SW2/BREAK)
 3. PA5(SW1/MAKE)
-4. PA6(BIT7)
+4. PA6(RELAY_READ)
 5. PA7(RELAY_OUT)
 6. PB3(BIT6)
 7. PB2(BIT5)