diff --git a/drivers/filters/mountmgr/device.c b/drivers/filters/mountmgr/device.c
index 17d720e346c..7172a3b5da8 100644
--- a/drivers/filters/mountmgr/device.c
+++ b/drivers/filters/mountmgr/device.c
@@ -1745,7 +1745,7 @@ MountMgrQueryPoints(IN PDEVICE_EXTENSION DeviceExtension,
 
     /* We can't go beyond */
     if (((ULONG)MountPoint->SymbolicLinkNameLength + MountPoint->UniqueIdLength +
-        MountPoint->DeviceNameLength) < Stack->Parameters.DeviceIoControl.InputBufferLength)
+        MountPoint->DeviceNameLength) > Stack->Parameters.DeviceIoControl.InputBufferLength)
     {
         return STATUS_INVALID_PARAMETER;
     }