diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 797f539..cba33ce 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -842,10 +842,11 @@ int ieee80211_register_hw(struct ieee80211_hw *hw)
 	/*
 	 * The hardware needs headroom for sending the frame,
 	 * and we need some headroom for passing the frame to monitor
-	 * interfaces, but never both at the same time.
+	 * interfaces. This may not be both at the same time, but
+	 * account for both to be safe.
 	 */
-	local->tx_headroom = max_t(unsigned int , local->hw.extra_tx_headroom,
-				   sizeof(struct ieee80211_tx_status_rtap_hdr));
+	local->tx_headroom = local->hw.extra_tx_headroom +
+				   sizeof(struct ieee80211_tx_status_rtap_hdr);
 
 	debugfs_hw_add(local);