diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 471d0605f7..1a381699ef 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6529,6 +6529,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             __put_user(stfs.f_fsid.__val[0], &target_stfs->f_fsid.val[0]);
             __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]);
             __put_user(stfs.f_namelen, &target_stfs->f_namelen);
+            __put_user(stfs.f_frsize, &target_stfs->f_frsize);
+            memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare));
             unlock_user_struct(target_stfs, arg2, 1);
         }
         break;
@@ -6557,6 +6559,8 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             __put_user(stfs.f_fsid.__val[0], &target_stfs->f_fsid.val[0]);
             __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]);
             __put_user(stfs.f_namelen, &target_stfs->f_namelen);
+            __put_user(stfs.f_frsize, &target_stfs->f_frsize);
+            memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare));
             unlock_user_struct(target_stfs, arg3, 1);
         }
         break;