diff --git a/scripts/install b/scripts/install
index d4bb1dca..38c75c49 100755
--- a/scripts/install
+++ b/scripts/install
@@ -66,7 +66,7 @@ ynh_app_setting_set $app database $database
 #=================================================
 # INSTALL DEPENDENCIES
 #=================================================
-ynh_install_app_dependencies php5-cli 'php5-imagick|php-imagick' php5-gd php5-mcrypt 'php-xml|base-files(<<9.0)'
+ynh_install_app_dependencies php-mbstring php5-cli 'php5-imagick|php-imagick' php5-gd php5-mcrypt 'php-xml|base-files(<<9.0)'
 
 #=================================================
 # CREATE A MYSQL DATABASE
diff --git a/scripts/restore b/scripts/restore
index 986691bc..3a90b668 100644
--- a/scripts/restore
+++ b/scripts/restore
@@ -83,7 +83,7 @@ ynh_restore_file "/etc/php5/fpm/conf.d/20-$app.ini"
 #=================================================
 # REINSTALL DEPENDENCIES
 #=================================================
-ynh_install_app_dependencies php5-cli 'php5-imagick|php-imagick' php5-gd php5-mcrypt 'php-xml|base-files(<<9.0)'
+ynh_install_app_dependencies php-mbstring php5-cli 'php5-imagick|php-imagick' php5-gd php5-mcrypt 'php-xml|base-files(<<9.0)'
 
 #=================================================
 # RESTORE THE CRON FILE
diff --git a/scripts/upgrade b/scripts/upgrade
index 04274cdc..adbeced0 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -129,7 +129,7 @@ sudo cp ../conf/poller-cron /etc/cron.d/$app
 #=================================================
 # INSTALL DEPENDENCIES
 #=================================================
-ynh_install_app_dependencies php5-cli 'php5-imagick|php-imagick' php5-gd php5-mcrypt 'php-xml|base-files(<<9.0)'
+ynh_install_app_dependencies php-mbstring php5-cli 'php5-imagick|php-imagick' php5-gd php5-mcrypt 'php-xml|base-files(<<9.0)'
 
 
 # Make app public