diff --git a/ispc3-ai.sh b/ispc3-ai.sh
index 49205f42519f4ea1f1333d2a6f607da5164773c6..01222274ba267366f558c0cb00775b6a238235f8 100755
--- a/ispc3-ai.sh
+++ b/ispc3-ai.sh
@@ -29,7 +29,7 @@ fi
 
 if [ "$PHP" = "" ] ; then
 	echo "PHP cli missing, trying to install." ;
-	apt-get update -qq && apt-get -y -qq install php-cli ;
+	apt-get update -qq && apt-get -y -qq install php-cli && apt-get -y -qq install php-mbstring ;
 	PHP=$(which php) ;
 fi
 if [ "$PHP" = "" ] ; then