diff --git a/README.md b/README.md
index 54d8c7a..b19e4f3 100644
--- a/README.md
+++ b/README.md
@@ -347,6 +347,9 @@ For example, if the domain name of the distillery instance is `wisski.example.co
 The resolver configuration is automatically updated by the `update_prefix_config.sh` script.
 It should not be neccessary to reload this configuration manually, as it is automatically called during `system_update.sh`.
 
+It is also possible to manually add a URI prefix to an instance.
+For this purpose, add a file named `prefixes` to the base directory of the instance, with one prefix per line.
+
 ## License
 
 This project and associated files in this repository are licensed as follows:
diff --git a/distillery/lib/30_slug.sh b/distillery/lib/30_slug.sh
index b312033..31bb1fe 100644
--- a/distillery/lib/30_slug.sh
+++ b/distillery/lib/30_slug.sh
@@ -66,6 +66,14 @@ GRAPHDB_REPO="${GRAPHDB_REPO_PREFIX}${USERNAME_BASE}"
 INSTANCE_BASE_DIR="$DEPLOY_INSTANCES_DIR/$INSTANCE_DOMAIN"
 INSTANCE_DATA_DIR="$INSTANCE_BASE_DIR/data/"
 
+# compute the prefix file
+function compute_instance_prefixfile() {
+    INSTANCE_BASE_DIR="$1"
+    INSTANCE_PREFIX_FILE="$INSTANCE_BASE_DIR/prefixes"
+    echo "$INSTANCE_PREFIX_FILE"
+}
+INSTANCE_PREFIX_FILE="$(compute_instance_prefixfile "$INSTANCE_BASE_DIR" )"
+
 if [ -n "$CERTBOT_EMAIL" ]; then
     LETSENCRYPT_HOST="$INSTANCE_DOMAIN"
     LETSENCRYPT_EMAIL="$CERTBOT_EMAIL"
diff --git a/distillery/update_prefix_config.sh b/distillery/update_prefix_config.sh
index 8cccb8b..20f059b 100644
--- a/distillery/update_prefix_config.sh
+++ b/distillery/update_prefix_config.sh
@@ -21,6 +21,12 @@ for slug in $(sql_bookkeep_list); do
     read -r INSTANCE_BASE_DIR MYSQL_DATABASE MYSQL_USER GRAPHDB_REPO GRAPHDB_USER GRAPHDB_PASSWORD <<< "$(sql_bookkeep_load "${slug}" "filesystem_base,sql_database,sql_user,graphdb_repository,graphdb_user,graphdb_password" | tail -n +2)"
 
     pushd "$INSTANCE_BASE_DIR" > /dev/null
+
+    INSTANCE_PREFIX_FILE="$(compute_instance_prefixfile "$INSTANCE_BASE_DIR" )"
+    if [ -f "$INSTANCE_PREFIX_FILE" ]; then
+        cat "$INSTANCE_PREFIX_FILE" | tee -a "$DEPLOY_PREFIX_CONFIG"
+    fi
+    
     docker-compose exec barrel /user_shell.sh -c "drush php:script /wisskiutils/list_uri_prefixes.php" | tee -a "$DEPLOY_PREFIX_CONFIG"
     popd > /dev/null
 done