1 files changed, 4 insertions, 2 deletions

diff --git a/src/man/firejail.txt b/src/man/firejail.txt
index 60c21cbc1..69ed2a8dc 100644
--- a/src/man/firejail.txt
+++ b/src/man/firejail.txt
@@ -76,7 +76,9 @@ $ firejail [OPTIONS] firefox        # starting Mozilla Firefox
 Signal the end of options and disables further option processing.
 .TP
 \fB\-\-allow-debuggers
-Allow tools such as strace and gdb inside the sandbox.
+Allow tools such as strace and gdb inside the sandbox. This option is only available
+when running on Linux kernels 4.8 or newer - a kernel bug in ptrace system call allows a full
+bypass of the seccomp filter.
 .br
 
 .br
@@ -676,7 +678,7 @@ $ firejail \-\-net=eth0 \-\-mac=00:11:22:33:44:55 firefox
 
 .TP
 \fB\-\-machine-id
-Preserve id number in /etc/machine-id file. By default a new random id is generated inside the sandbox.
+Spoof id number in /etc/machine-id file - a new random id is generated inside the sandbox.
 .br
 
 .br