diff --git a/Changes b/Changes
index b0a3853753..3b48a9951c 100644
--- a/Changes
+++ b/Changes
@@ -31,6 +31,7 @@ inventory:
 * Fix #439: Wrong network interface speed under win32
 * Fix #472: On MacOS, add monitors serial number when available
 * Fix #479: No virtual machine memory under Proxmox
+* Fix #485: Fix df output parsing under MacOS
 * Fix #500: Add Acer monitor EDID id match
 * Better SQL Server software inventory under win32
 * Update Xen Server support
diff --git a/lib/FusionInventory/Agent/Task/Inventory/MacOS/Drives.pm b/lib/FusionInventory/Agent/Task/Inventory/MacOS/Drives.pm
index 098ae8506a..ef3c94d3c4 100644
--- a/lib/FusionInventory/Agent/Task/Inventory/MacOS/Drives.pm
+++ b/lib/FusionInventory/Agent/Task/Inventory/MacOS/Drives.pm
@@ -45,7 +45,7 @@ sub doInventory {
         my $filesystem = $filesystems{$device};
         next unless $filesystem;
 
-        if ($info->{'Total Size'} =~ /^([.\d]+ \s \S+)/x) {
+        if ($info->{'Total Size'} && $info->{'Total Size'} =~ /^([.\d]+ \s \S+)/x) {
             $filesystem->{TOTAL} = getCanonicalSize($1);
         }
         $filesystem->{SERIAL}     = $info->{'Volume UUID'} ||