diff --git a/bin/installto.sh b/bin/installto.sh
index 269a5dc06..fbd951bdf 100755
--- a/bin/installto.sh
+++ b/bin/installto.sh
@@ -71,7 +71,7 @@ if (strtolower($input) == 'y') {
 
   if (!$err) {
     echo "Running update script at target...\n";
-    system("cd $target_dir && bin/update.sh --version=$oldversion");
+    system("cd $target_dir && php bin/update.sh --version=$oldversion");
     echo "All done.\n";
   }
 }
diff --git a/bin/update.sh b/bin/update.sh
index 8bfb9d603..9b72ef3bf 100755
--- a/bin/update.sh
+++ b/bin/update.sh
@@ -157,7 +157,7 @@ if ($RCI->configured) {
   // check database schema
   if ($RCI->config['db_dsnw']) {
     echo "Executing database schema update.\n";
-    system(INSTALL_PATH . "bin/updatedb.sh --package=roundcube --version=" . $opts['version']
+    system("php " . INSTALL_PATH . "bin/updatedb.sh --package=roundcube --version=" . $opts['version']
       . " --dir=" . INSTALL_PATH . DIRECTORY_SEPARATOR . "SQL", $res);
 
     $success = !$res;
@@ -165,7 +165,7 @@ if ($RCI->configured) {
 
   // index contacts for fulltext searching
   if ($opts['version'] && version_compare(version_parse($opts['version']), '0.6.0', '<')) {
-    system(INSTALL_PATH . 'bin/indexcontacts.sh');
+    system("php " . INSTALL_PATH . 'bin/indexcontacts.sh');
   }
 
   if ($success) {