diff --git a/scripts/install b/scripts/install
index 4fae671..5f1d484 100644
--- a/scripts/install
+++ b/scripts/install
@@ -101,6 +101,7 @@ test ! -e /etc/matrix-$app/dh.pem && \
 # For any update do it in all files
 ynh_install_app_dependencies coturn build-essential python2.7-dev libffi-dev python-pip python-setuptools sqlite3 libssl-dev python-virtualenv libxml2-dev libxslt1-dev python-lxml libjpeg-dev libpq-dev postgresql acl
 pip install --upgrade pip
+hash -d pip
 pip install --upgrade virtualenv
 
 #=================================================
diff --git a/scripts/restore b/scripts/restore
index cf0f468..c93a920 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -61,6 +61,7 @@ ynh_restore
 # For any update do it in all files
 ynh_install_app_dependencies coturn build-essential python2.7-dev libffi-dev python-pip python-setuptools sqlite3 libssl-dev python-virtualenv libxml2-dev libxslt1-dev python-lxml libjpeg-dev libpq-dev postgresql acl
 pip install --upgrade pip
+hash -d pip
 pip install --upgrade virtualenv
 
 #=================================================
diff --git a/scripts/upgrade b/scripts/upgrade
index fac42ea..58a46c6 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -121,6 +121,7 @@ then
     # For any update do it in all files
     ynh_install_app_dependencies coturn build-essential python2.7-dev libffi-dev python-pip python-setuptools sqlite3 libssl-dev python-virtualenv libxml2-dev libxslt1-dev python-lxml libjpeg-dev libpq-dev postgresql acl
     pip install --upgrade pip
+    hash -d pip
     pip install --upgrade virtualenv
 
     #=================================================
@@ -172,6 +173,7 @@ else
     # We set all necessary environement variable to create a python virtualenvironnement. 
     source $final_path/bin/activate
     pip install --upgrade pip
+    hash -d pip
     pip install --upgrade setuptools
     pip install --upgrade cffi ndg-httpsclient psycopg2 lxml