1 files changed, 1 insertions, 1 deletions

diff --git a/plugins/check_disk.c b/plugins/check_disk.c
index 09c6b0a1..3beb5689 100644
--- a/plugins/check_disk.c
+++ b/plugins/check_disk.c
@@ -191,7 +191,7 @@ main (int argc, char **argv)
                         psize = fsp.fsu_blocks*fsp.fsu_blocksize/mult;
                         asprintf (&perf, "%s %s", perf,
                                   perfdata ((!strcmp(file_system, "none") || display_mntp) ? me->me_devname : me->me_mountdir,
-                                            fsp.fsu_bavail*fsp.fsu_blocksize/mult, units,
+                                            psize-(fsp.fsu_bavail*fsp.fsu_blocksize/mult), units,
                                             TRUE, min ((uintmax_t)psize-(uintmax_t)w_df, (uintmax_t)((1.0-w_dfp/100.0)*psize)),
                                             TRUE, min ((uintmax_t)psize-(uintmax_t)c_df, (uintmax_t)((1.0-c_dfp/100.0)*psize)),
                                             TRUE, 0,