diff --git a/scripts/_common.sh b/scripts/_common.sh
index 6cac827..933f113 100755
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -1 +1,50 @@
 dependances="coturn build-essential python3-dev libffi-dev python3-pip python3-setuptools sqlite3 libssl-dev python3-venv libxml2-dev libxslt1-dev python3-lxml libjpeg-dev libpq-dev postgresql acl"
+python_version="$(python3 -V | cut -d' ' -f2 | cut -d. -f1-2)"
+
+install_sources() {
+    # Install/upgrade synapse in virtualenv
+
+    # Clean venv is it was on python2.7 or python3 with old version in case major upgrade of debian
+    if [ ! -e $final_path/bin/python3 ] || [ ! -e $final_path/lib/python$python_version ]; then
+        ynh_secure_remove --file=$final_path
+    fi
+
+    mkdir -p $final_path
+
+    if [ -n "$(uname -m | grep arm)" ]
+    then
+        # Clean old file, sometimes it could make some big issues if we don't do this!!
+        ynh_secure_remove --file=$final_path/bin
+        ynh_secure_remove --file=$final_path/lib
+        ynh_secure_remove --file=$final_path/include
+        ynh_secure_remove --file=$final_path/share
+
+        ynh_setup_source --dest_dir=$final_path/ --source_id="armv7_$(lsb_release --codename --short)"
+
+        # Fix multi-instance support
+        for f in $(ls $final_path/bin); do
+            if ! [[ $f =~ "__" ]]; then
+                ynh_replace_special_string --match_string='#!/opt/yunohost/matrix-synapse' --replace_string='#!'$final_path --target_file=$final_path/bin/$f
+            fi
+        done
+    else
+        # Install virtualenv if it don't exist
+        test -e $final_path/bin/python3 || python3 -m venv $final_path
+
+        # Install synapse in virtualenv
+        ynh_replace_string --match_string=__FINAL_PATH__ --replace_string=$final_path --target_file=$final_path/bin/activate
+
+        # We set all necessary environement variable to create a python virtualenvironnement.
+        set +u;
+        source $final_path/bin/activate
+        set -u;
+        pip3 install --upgrade setuptools wheel
+        pip3 install --upgrade cffi ndg-httpsclient psycopg2 lxml jinja2
+        pip3 install --upgrade 'Twisted>=20.3.0' matrix-synapse==$upstream_version matrix-synapse-ldap3
+
+        # This function was defined when we called "source $final_path/bin/activate". With this function we undo what "$final_path/bin/activate" does
+        set +u;
+        deactivate
+        set -u;
+    fi
+}
diff --git a/scripts/install b/scripts/install
index db835d9..cf5141b 100644
--- a/scripts/install
+++ b/scripts/install
@@ -175,40 +175,9 @@ ynh_script_progression --message="Setting up source files..." --weight=50
 mkdir -p /var/lib/matrix-$app
 mkdir -p /var/log/matrix-$app
 mkdir -p /etc/matrix-$app/conf.d
-mkdir -p $final_path
 
 # Install synapse in virtualenv
-
-# WARNING : theses command are used in INSTALL, UPGRADE (2 times)
-# For any update do it in all files
-if [ -n "$(uname -m | grep arm)" ]
-then
-    ynh_setup_source --dest_dir=$final_path/ --source_id="armv7_$(lsb_release --codename --short)"
-
-    # Fix multi-instance support
-    for f in $(ls $final_path/bin); do
-        if ! [[ $f =~ "__" ]]; then
-            ynh_replace_special_string --match_string='#!/opt/yunohost/matrix-synapse' --replace_string='#!'$final_path --target_file=$final_path/bin/$f
-        fi
-    done
-else
-    # Install virtualenv if it don't exist
-    test -e $final_path/bin/python3 || python3 -m venv $final_path
-
-    # Install synapse in virtualenv
-    cp ../conf/virtualenv_activate $final_path/bin/activate
-    ynh_replace_string --match_string=__FINAL_PATH__ --replace_string=$final_path --target_file=$final_path/bin/activate
-
-    # We set all necessary environement variable to create a python virtualenvironnement.
-    source $final_path/bin/activate
-    pip3 install --upgrade pip
-    pip3 install --upgrade setuptools wheel
-    pip3 install --upgrade cffi ndg-httpsclient psycopg2 lxml jinja2
-    pip3 install --upgrade matrix-synapse==$upstream_version matrix-synapse-ldap3
-
-    # This function was defined when we called "source $final_path/bin/activate". With this function we undo what "$final_path/bin/activate" does
-    deactivate
-fi
+install_sources
 
 #=================================================
 # CREATE SMALL CAS SERVER
@@ -228,14 +197,17 @@ chown $synapse_user:root -R $final_www_path
 ynh_script_progression --message="Creating synapse config..." --weight=3
 
 # Go in virtualenvironnement
-PS1=${PS1:-}
+set +u;
 source $final_path/bin/activate
+set -u;
 
 # Generate config
 python -m synapse.app.homeserver --keys-directory /etc/matrix-$app/ --generate-config --generate-keys --server-name $server_name --report-stats=no -c homeserver.yml
 
 # This function was defined when we called "source $final_path/bin/activate". With this function we undo what "$final_path/bin/activate" does
+set +u;
 deactivate
+set -u;
 
 # Get random values from config
 ynh_print_OFF
diff --git a/scripts/restore b/scripts/restore
index c0d4616..5a11cd1 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -69,6 +69,10 @@ test ! -d $final_path \
 ynh_script_progression --message="Restoring directory and configuration..." --weight=10
 ynh_restore
 
+# Check that the good python version is installed
+# If not upgrade the source
+install_sources
+
 #=================================================
 # RESTORE FAIL2BAN CONFIGURATION
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index 27c86b8..e3b7d3e 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -143,48 +143,7 @@ ynh_install_app_dependencies $dependances
 if [ "$upgrade_type" == "UPGRADE_APP" ]
 then
 	ynh_script_progression --message="Upgrading source files..." --weight=6
-
-	# Install/upgrade synapse in virtualenv
-
-	# Clean venv is it was on python2.7
-	test -e $final_path/bin/python3 || ynh_secure_remove --file=$final_path
-
-	# WARNING : these commands are used in INSTALL, UPGRADE
-	# For any update do it in all files
-
-	if [ -n "$(uname -m | grep arm)" ]
-	then
-		# Clean old file, sometimes it could make some big issues if we don't do this!!
-		ynh_secure_remove --file=$final_path/bin
-		ynh_secure_remove --file=$final_path/lib
-		ynh_secure_remove --file=$final_path/include
-		ynh_secure_remove --file=$final_path/share
-
-		ynh_setup_source --dest_dir=$final_path/ --source_id="armv7_$(lsb_release --codename --short)"
-
-		# Fix multi-instance support
-		for f in $(ls $final_path/bin); do
-			if ! [[ $f =~ "__" ]]; then
-				ynh_replace_special_string --match_string='#!/opt/yunohost/matrix-synapse' --replace_string='#!'$final_path --target_file=$final_path/bin/$f
-			fi
-		done
-	else
-		# Install virtualenv if it don't exist
-		test -e $final_path/bin/python3 || python3 -m venv $final_path
-
-		# Install synapse in virtualenv
-		cp ../conf/virtualenv_activate $final_path/bin/activate
-		ynh_replace_string --match_string=__FINAL_PATH__ --replace_string=$final_path --target_file=$final_path/bin/activate
-
-		# We set all necessary environement variable to create a python virtualenvironnement.
-		source $final_path/bin/activate
-		pip3 install --upgrade setuptools wheel
-		pip3 install --upgrade cffi ndg-httpsclient psycopg2 lxml jinja2
-		pip3 install --upgrade 'Twisted>=20.3.0' matrix-synapse==$upstream_version matrix-synapse-ldap3
-
-		# This function was defined when we called "source $final_path/bin/activate". With this function we undo what "$final_path/bin/activate" does
-		deactivate
-	fi
+	install_sources
 fi
 
 #=================================================