diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index d7e4bd5..ace3934 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2133,7 +2133,7 @@
 	if (nfserr)
 		goto out;
 
-	RESERVE_SPACE(36 + sizeof(stateid_t));
+	RESERVE_SPACE(40 + sizeof(stateid_t));
 	WRITE32(open->op_stateid.si_generation);
 	WRITEMEM(&open->op_stateid.si_opaque, sizeof(stateid_opaque_t));
 	WRITECINFO(open->op_cinfo);