diff --git a/README.md b/README.md
index 57e4cf6ff2c02cd87bc55ff33a54405b4fa538b4..5f5383b0e6f37a3b1328407820476986211fa97c 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,30 @@ For now it does 2 things:
 Either put `https://github.com/neutrinet/neutrinet_ynh` in the administration interface at the bottom of the installation page or do this command in ssh:
 
     yunohost app install https://github.com/Neutrinet/neutrinet_ynh --verbose
+
+
+# Known and "normal" warning/error messages during installation
+
+If you see those, don't worry, it's not a bug.
+
+After `+ sudo virtualenv ve --system-site-packages`
+
+    Compiling /tmp/pip-build-0Vk8QK/pexpect/pexpect/async.py ...
+      File "/tmp/pip-build-0Vk8QK/pexpect/pexpect/async.py", line 16
+        transport, pw = yield from asyncio.get_event_loop()\
+                                 ^
+    SyntaxError: invalid syntax
+
+This is due to the fact that we don't use python3 but python2 and that doesn't change anything here.
+
+After `Running command 'yunohost app setting vpnclient login_passphrase -v "xxxxxxxxxxxxxxxxxxxxx"' ... done`
+
+    Failed to open /dev/tty: No such device or address
+    Failed to open /dev/tty: No such device or address
+    Failed to open /dev/tty: No such device or address
+    Failed to open /dev/tty: No such device or address
+    Failed to open /dev/tty: No such device or address
+    Failed to open /dev/tty: No such device or address
+    Failed to open /dev/tty: No such device or address
+
+It doesn't prevent the script from running.