diff --git a/internal/steppir/steppir.go b/internal/steppir/steppir.go
index 4e6551c..bf79136 100644
--- a/internal/steppir/steppir.go
+++ b/internal/steppir/steppir.go
@@ -253,10 +253,14 @@ func parseStatus(b []byte) (*Status, error) {
 	freqHz := int(int32(binary.BigEndian.Uint32(b[2:6]))) * 10
 	active := b[6]
 	dir := decodeDir(b[7])
-	// active==0xFF means "command just received" (not motion); the 0x01 bit is
-	// documented as always set. Treat anything else non-zero as motors busy.
+	// active-motors byte: one bit per element that is currently moving.
+	//   0x04 driver · 0x08 DIR1 · 0x10 reflector · 0x20 DIR2  (mask 0x3C)
+	// Bit 0 (0x01) is documented as always set — not a motor. 0xFF means the
+	// controller just received a command, not motion. So "moving" is precisely
+	// "any real motor bit set", ignoring the always-on bit and the ack value.
+	const motorBits = 0x3C
 	moving := 0
-	if active != 0xFF && (active & ^byte(0x01)) != 0 {
+	if active != 0xFF && active&motorBits != 0 {
 		moving = 1
 	}
 	return &Status{Frequency: freqHz / 1000, Direction: dir, MotorsMoving: moving}, nil