diff --git a/openbis/dist/server/install.sh b/openbis/dist/server/install.sh
index 510100ce8502e34da997f684cec99858bfdb8805..95af7b1e33d0e3725003938f74abb87d1d7b0c7e 100755
--- a/openbis/dist/server/install.sh
+++ b/openbis/dist/server/install.sh
@@ -101,7 +101,7 @@ echo "Make the configuration checksum file available : " $checksum_file
 test -f "$checksum_file" && cp -p "$checksum_file" "$jetty_folder"
 
 echo installing core-plugins
-unzip -qu "$installation_folder/core-plugins.zip" -d "$server_folder/.."
+unzip -quo "$installation_folder/core-plugins.zip" -d "$server_folder/.."
 
 # Move config files to etc and create symlinks.
 mv "$war_classes/etc/log.xml" "$JETTY_ETC_DIR"