diff --git a/src/add-ons/kernel/file_systems/nfs4/Inode.cpp b/src/add-ons/kernel/file_systems/nfs4/Inode.cpp
index 53a76a453f..dd7ade5340 100644
--- a/src/add-ons/kernel/file_systems/nfs4/Inode.cpp
+++ b/src/add-ons/kernel/file_systems/nfs4/Inode.cpp
@@ -892,6 +892,8 @@ bool
 Inode::_HandleErrors(uint32 nfs4Error, RPC::Server* serv,
 	OpenFileCookie* cookie)
 {
+	uint32 leaseTime;
+
 	switch (nfs4Error) {
 		case NFS4_OK:
 			return false;
@@ -900,11 +902,12 @@ Inode::_HandleErrors(uint32 nfs4Error, RPC::Server* serv,
 		case NFS4ERR_LOCKED:
 		case NFS4ERR_DELAY:
 			if (cookie == NULL) {
-				snooze_etc(5 * 1000000, B_SYSTEM_TIMEBASE, B_RELATIVE_TIMEOUT);
+				snooze_etc(sSecToBigTime(5), B_SYSTEM_TIMEBASE,
+					B_RELATIVE_TIMEOUT);
 				return true;
 			} else if ((cookie->fMode & O_NONBLOCK) == 0) {
 				status_t result = acquire_sem_etc(cookie->fSnoozeCancel, 1,
-					B_RELATIVE_TIMEOUT, 5 * 1000000);
+					B_RELATIVE_TIMEOUT, sSecToBigTime(5));
 				if (result == B_TIMED_OUT)
 					return true;
 				else {
@@ -916,14 +919,14 @@ Inode::_HandleErrors(uint32 nfs4Error, RPC::Server* serv,
 
 		// server is in grace period, we need to wait
 		case NFS4ERR_GRACE:
+			leaseTime = fFilesystem->NFSServer()->LeaseTime();
 			if (cookie == NULL) {
-				snooze_etc(fFilesystem->NFSServer()->LeaseTime() / 3,
-					B_SYSTEM_TIMEBASE, B_RELATIVE_TIMEOUT);
+				snooze_etc(sSecToBigTime(leaseTime) / 3, B_SYSTEM_TIMEBASE,
+					B_RELATIVE_TIMEOUT);
 				return true;
 			} else if ((cookie->fMode & O_NONBLOCK) == 0) {
 				status_t result = acquire_sem_etc(cookie->fSnoozeCancel, 1,
-					B_RELATIVE_TIMEOUT,
-					fFilesystem->NFSServer()->LeaseTime() / 3);
+					B_RELATIVE_TIMEOUT, sSecToBigTime(leaseTime) / 3);
 				if (result == B_TIMED_OUT)
 					return true;
 				else {
@@ -952,6 +955,14 @@ Inode::_HandleErrors(uint32 nfs4Error, RPC::Server* serv,
 			fFilesystem->Migrate(serv);
 			return true;
 
+		// lease has expired
+		case NFS4ERR_EXPIRED:
+			if (cookie != NULL) {
+				fFilesystem->NFSServer()->ClientId(cookie->fClientId, true);
+				return true;
+			} else
+				return false;
+
 		default:
 			return false;
 	}
diff --git a/src/add-ons/kernel/file_systems/nfs4/NFS4Defs.h b/src/add-ons/kernel/file_systems/nfs4/NFS4Defs.h
index 813586a667..f83cc011d4 100644
--- a/src/add-ons/kernel/file_systems/nfs4/NFS4Defs.h
+++ b/src/add-ons/kernel/file_systems/nfs4/NFS4Defs.h
@@ -309,5 +309,12 @@ enum Errors {
 };
 
 
+static inline bigtime_t
+sSecToBigTime(uint32 sec)
+{
+	return static_cast<bigtime_t>(sec) * 1000000;
+}
+
+
 #endif	// NFS4DEFS_H
 
diff --git a/src/add-ons/kernel/file_systems/nfs4/NFS4Server.cpp b/src/add-ons/kernel/file_systems/nfs4/NFS4Server.cpp
index 80a54b545f..6fd109e7b3 100644
--- a/src/add-ons/kernel/file_systems/nfs4/NFS4Server.cpp
+++ b/src/add-ons/kernel/file_systems/nfs4/NFS4Server.cpp
@@ -181,7 +181,7 @@ uint64
 NFS4Server::ClientId(uint64 prevId, bool forceNew)
 {
 	MutexLocker _(fClientIdLock);
-	if (fClientIdLastUse + (time_t)LeaseTime() < time(NULL)
+	if (fUseCount == 0 && fClientIdLastUse + (time_t)LeaseTime() < time(NULL)
 		|| forceNew && fClientId == prevId) {
 
 		Request request(fServer);
@@ -256,7 +256,7 @@ NFS4Server::_GetLeaseTime()
 		return B_BAD_VALUE;
 	}
 
-	fLeaseTime = values[0].fData.fValue32 * 1000000;
+	fLeaseTime = values[0].fData.fValue32;
 
 	return B_OK;
 }
@@ -295,8 +295,8 @@ NFS4Server::_Renewal()
 {
 	while (!fThreadCancel) {
 		// TODO: operations like OPEN, READ, CLOSE, etc also renew leases
-		snooze_etc(fLeaseTime - 2, B_SYSTEM_TIMEBASE, B_RELATIVE_TIMEOUT
-			| B_CAN_INTERRUPT);
+		snooze_etc(sSecToBigTime(fLeaseTime - 2), B_SYSTEM_TIMEBASE,
+			B_RELATIVE_TIMEOUT | B_CAN_INTERRUPT);
 
 		uint64 clientId = fClientId;