diff --git a/sys/dev/ath/if_ath.c b/sys/dev/ath/if_ath.c
index 2c04c8ee53c..dde23cde82d 100644
--- a/sys/dev/ath/if_ath.c
+++ b/sys/dev/ath/if_ath.c
@@ -262,7 +262,7 @@ ath_attach(u_int16_t devid, struct ath_softc *sc)
 		if_printf(ifp, "failed to allocate descriptors: %d\n", error);
 		goto bad;
 	}
-	callout_init(&sc->sc_scan_ch, CALLOUT_MPSAFE);
+	callout_init(&sc->sc_scan_ch, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
 	callout_init(&sc->sc_cal_ch, CALLOUT_MPSAFE);
 
 	ATH_TXBUF_LOCK_INIT(sc);