diff --git a/sys/nfsserver/nfs.h b/sys/nfsserver/nfs.h
index 262e7371a10f..5295b6900fcc 100644
--- a/sys/nfsserver/nfs.h
+++ b/sys/nfsserver/nfs.h
@@ -134,6 +134,7 @@ extern struct nfsrvstats nfsrvstats;
 extern int	nfsrv_ticks;
 extern int	nfsrvw_procrastinate;
 extern int	nfsrvw_procrastinate_v3;
+extern int 	nfsrv_numnfsd;
 
 /* Various values converted to XDR form. */
 extern u_int32_t nfsrv_nfs_false, nfsrv_nfs_true, nfsrv_nfs_xdrneg1,
diff --git a/sys/nfsserver/nfs_srvsubs.c b/sys/nfsserver/nfs_srvsubs.c
index 4146e730f99a..9da4b1a6843c 100644
--- a/sys/nfsserver/nfs_srvsubs.c
+++ b/sys/nfsserver/nfs_srvsubs.c
@@ -551,6 +551,8 @@ nfsrv_modevent(module_t mod, int type, void *data)
 		break;
 
 		case MOD_UNLOAD:
+		if (nfsrv_numnfsd != 0)
+			return EBUSY;
 
 		callout_stop(&nfsrv_callout);
 		sysent[SYS_nfssvc].sy_narg = nfs_prev_nfssvc_sy_narg;
diff --git a/sys/nfsserver/nfs_syscalls.c b/sys/nfsserver/nfs_syscalls.c
index e947ee62fc46..c3b097e3d7ba 100644
--- a/sys/nfsserver/nfs_syscalls.c
+++ b/sys/nfsserver/nfs_syscalls.c
@@ -86,7 +86,7 @@ MALLOC_DEFINE(M_NFSD, "NFS daemon", "Nfs server daemon structure");
 SYSCTL_DECL(_vfs_nfsrv);
 
 int		nfsd_waiting = 0;
-static int	nfs_numnfsd = 0;
+int		nfsrv_numnfsd = 0;
 static int	notstarted = 1;
 
 static int	nfs_privport = 0;
@@ -304,7 +304,7 @@ nfssvc_nfsd(struct thread *td)
 	s = splnet();
 	nfsd->nfsd_td = td;
 	TAILQ_INSERT_TAIL(&nfsd_head, nfsd, nfsd_chain);
-	nfs_numnfsd++;
+	nfsrv_numnfsd++;
 
 	/*
 	 * Loop getting rpc requests until SIGKILL.
@@ -533,7 +533,7 @@ nfssvc_nfsd(struct thread *td)
 	TAILQ_REMOVE(&nfsd_head, nfsd, nfsd_chain);
 	splx(s);
 	free((caddr_t)nfsd, M_NFSD);
-	if (--nfs_numnfsd == 0)
+	if (--nfsrv_numnfsd == 0)
 		nfsrv_init(TRUE);	/* Reinitialize everything */
 	return (error);
 }