diff --git a/mt7921/mac.c b/mt7921/mac.c
index 85434996..1c2377d0 100644
--- a/mt7921/mac.c
+++ b/mt7921/mac.c
@@ -531,8 +531,9 @@ static void mt7921_mac_tx_free(struct mt792x_dev *dev, void *data, int len)
 		stat = FIELD_GET(MT_TX_FREE_STATUS, info);
 
 		if (wcid) {
-			wcid->stats.tx_retries +=
-				FIELD_GET(MT_TX_FREE_COUNT, info) - 1;
+			u32 count = FIELD_GET(MT_TX_FREE_COUNT, info);
+
+			wcid->stats.tx_retries += count ? count - 1 : 0;
 			wcid->stats.tx_failed += !!stat;
 		}