diff --git a/src/freedombone-app-radicale b/src/freedombone-app-radicale
index 67fc6c8dd10e0bceec8f777ea5bc7ccf848d1aff..d50ff410f2c944629b8a3cadd90a28282888e62c 100755
--- a/src/freedombone-app-radicale
+++ b/src/freedombone-app-radicale
@@ -55,7 +55,7 @@ function remove_user_radicale {
 
     ${PROJECT_NAME}-pass -u $remove_username --rmapp radicale
 
-    if grep "${remove_username}:" ${RADICALE_USERS}; then
+    if grep -q "${remove_username}:" ${RADICALE_USERS}; then
         sed -i "/${remove_username}:/d" ${RADICALE_USERS}
         if [ -d /var/www/radicale/collections/${remove_username} ]; then
             rm -rf /var/www/radicale/collections/${remove_username}
@@ -77,7 +77,7 @@ function add_user_radicale {
         touch ${RADICALE_USERS}
     fi
 
-    if ! grep "$new_username:" ${RADICALE_USERS}; then
+    if ! grep -q "$new_username:" ${RADICALE_USERS}; then
         htpasswd -bd ${RADICALE_USERS} "$new_username" "$new_user_password"
 
         echo '{"ICAL:calendar-color": "#9e50df"}' > /var/www/radicale/collections/${new_username}.props
@@ -101,7 +101,7 @@ function change_password_radicale {
 
     ${PROJECT_NAME}-pass -u $existing_username -a radicale -p "$new_user_password"
 
-    if grep "${existing_username}:" ${RADICALE_USERS}; then
+    if grep -q "${existing_username}:" ${RADICALE_USERS}; then
         sed -i "/${existing_username}:/d" ${RADICALE_USERS}
         htpasswd -bd ${RADICALE_USERS} "$existing_username" "$new_user_password"
         systemctl reload radicale
@@ -513,7 +513,7 @@ function install_radicale {
         set_completion_param "radicale onion domain" "${RADICALE_ONION_HOSTNAME}"
     else
         # alter the existing site config
-        if ! grep "# Start radicale" /etc/nginx/sites-available/${DEFAULT_DOMAIN_NAME}; then
+        if ! grep -q "# Start radicale" /etc/nginx/sites-available/${DEFAULT_DOMAIN_NAME}; then
             sed -i '/ 443/a    # Start radicale\n  location @radicale {\n    auth_basic "Radicale";\n    auth_basic_user_file /var/www/radicale/users;\n    proxy_pass http://localhost:52322;\n    proxy_buffering off;\n    proxy_set_header Host $host;\n    proxy_set_header X-Real-IP $remote_addr;\n    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;\n    proxy_set_header X-Forwarded-Proto $scheme;\n  }\n\n  location /radicale {\n      try_files $uri @radicale;\n  }\n\n  location /.well-known/carddav {\n      try_files $uri @radicale;\n  }\n\n  location /.well-known/caldav {\n      try_files $uri @radicale;\n  }\n    # End radicale' /etc/nginx/sites-available/${DEFAULT_DOMAIN_NAME}
             sed -i '/listen localhost/a    # Start radicale\n  location @radicale {\n    auth_basic "Radicale";\n    auth_basic_user_file /var/www/radicale/users;\n    proxy_pass http://localhost:52322;\n    proxy_buffering off;\n    proxy_set_header Host $host;\n    proxy_set_header X-Real-IP $remote_addr;\n    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;\n    proxy_set_header X-Forwarded-Proto $scheme;\n  }\n\n  location /radicale {\n      try_files $uri @radicale;\n  }\n\n  location /.well-known/carddav {\n      try_files $uri @radicale;\n  }\n\n  location /.well-known/caldav {\n      try_files $uri @radicale;\n  }\n    # End radicale' /etc/nginx/sites-available/${DEFAULT_DOMAIN_NAME}
         fi