diff --git a/hw/misc/mac_via.c b/hw/misc/mac_via.c
index 9f9c2815d0..3c41d6263d 100644
--- a/hw/misc/mac_via.c
+++ b/hw/misc/mac_via.c
@@ -702,6 +702,12 @@ static void adb_via_send(MOS6522Q800VIA1State *v1s, int state, uint8_t data)
         break;
 
     case ADB_STATE_IDLE:
+        ms->b |= VIA1B_vADBInt;
+        adb_autopoll_unblock(adb_bus);
+
+        trace_via1_adb_send("IDLE", data,
+                            (ms->b & VIA1B_vADBInt) ? "+" : "-");
+
         return;
     }