diff --git a/ChangeLog b/ChangeLog
index c0f5481..fb2a136 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2016-05-21  Niibe Yutaka  <gniibe@fsij.org>
+
+	* src/main.c (led_blink, main): Fix LED blink protocol.
+
 2016-05-20  NIIBE Yutaka  <gniibe@fsij.org>
 
 	* VERSION: 1.2.0.
diff --git a/src/gnuk.h b/src/gnuk.h
index 1247a82..eed40c1 100644
--- a/src/gnuk.h
+++ b/src/gnuk.h
@@ -421,10 +421,11 @@ extern const uint8_t gnuk_string_serial[];
 #define LED_ONESHOT		  1
 #define LED_TWOSHOTS		  2
 #define LED_SHOW_STATUS		  4
-#define LED_START_COMMAND	  8
-#define LED_FINISH_COMMAND	 16
-#define LED_FATAL		 32
-#define LED_GNUK_EXEC		 64
+#define LED_FATAL		  8
+#define LED_SYNC	         16
+#define LED_GNUK_EXEC		 32
+#define LED_START_COMMAND	 64
+#define LED_FINISH_COMMAND	128
 void led_blink (int spec);
 
 #if defined(PINPAD_SUPPORT)
diff --git a/src/main.c b/src/main.c
index e9c58e3..6604797 100644
--- a/src/main.c
+++ b/src/main.c
@@ -158,6 +158,12 @@ static void display_status_code (void)
 void
 led_blink (int spec)
 {
+  if (spec == LED_START_COMMAND || spec == LED_FINISH_COMMAND)
+    {
+      led_inverted = (spec == LED_START_COMMAND);
+      spec = LED_SYNC;
+    }
+
   eventflag_signal (&led_event, spec);
 }
 
@@ -256,18 +262,12 @@ main (int argc, char *argv[])
 	case LED_SHOW_STATUS:
 	  display_status_code ();
 	  break;
-	case LED_START_COMMAND:
-	  set_led (1);
-	  led_inverted = 1;
-	  chopstx_usec_wait (LED_TIMEOUT_STOP);
-	  break;
-	case LED_FINISH_COMMAND:
-	  led_inverted = 0;
-	  set_led (0);
-	  break;
 	case LED_FATAL:
 	  display_fatal_code ();
 	  break;
+	case LED_SYNC:
+	  set_led (led_inverted);
+	  break;
 	case LED_GNUK_EXEC:
 	  goto exec;
 	default: