diff --git a/sys/dev/if_ndis/if_ndis.c b/sys/dev/if_ndis/if_ndis.c
index ee63661..55020c1 100644
--- a/sys/dev/if_ndis/if_ndis.c
+++ b/sys/dev/if_ndis/if_ndis.c
@@ -534,7 +534,8 @@ ndis_attach(dev)
 
 	sc = device_get_softc(dev);
 
-	KeInitializeSpinLock(&sc->ndis_spinlock);
+	mtx_init(&sc->ndis_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
+	    MTX_DEF);
 	KeInitializeSpinLock(&sc->ndis_rxlock);
 	InitializeListHead(&sc->ndis_shlist);
 
diff --git a/sys/dev/if_ndis/if_ndisvar.h b/sys/dev/if_ndis/if_ndisvar.h
index bf4f056..eaccb42 100644
--- a/sys/dev/if_ndis/if_ndisvar.h
+++ b/sys/dev/if_ndis/if_ndisvar.h
@@ -129,7 +129,7 @@ struct ndis_softc {
 	struct resource		*ndis_res_cm;	/* common mem (pccard) */
 	struct resource_list	ndis_rl;
 	int			ndis_rescnt;
-	kspin_lock		ndis_spinlock;
+	struct mtx		ndis_mtx;
 	uint8_t			ndis_irql;
 	device_t		ndis_dev;
 	int			ndis_unit;
@@ -183,7 +183,5 @@ struct ndis_softc {
 				    enum ieee80211_state, int);
 };
 
-#define NDIS_LOCK(_sc)		KeAcquireSpinLock(&(_sc)->ndis_spinlock, \
-				    &(_sc)->ndis_irql);
-#define NDIS_UNLOCK(_sc)	KeReleaseSpinLock(&(_sc)->ndis_spinlock, \
-				    (_sc)->ndis_irql);
+#define NDIS_LOCK(_sc)		mtx_lock(&(_sc)->ndis_mtx)
+#define NDIS_UNLOCK(_sc)	mtx_unlock(&(_sc)->ndis_mtx)