diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 4fd0c25..f52e9251 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -589,6 +589,13 @@
 		}
 	}
 
+	if (idx < 0) {
+		WARNING(rt2x00dev, "Frame received with unrecognized signal,"
+			"signal=0x%.2x, plcp=%d.\n", rxdesc->signal,
+			!!(rxdesc->dev_flags & RXDONE_SIGNAL_PLCP));
+		idx = 0;
+	}
+
 	/*
 	 * Only update link status if this is a beacon frame carrying our bssid.
 	 */