diff --git a/startup.sh b/startup.sh
index 9195d26..8c3317c 100755
--- a/startup.sh
+++ b/startup.sh
@@ -109,6 +109,12 @@ if [ "${POSTGRES_JNDI_ENABLED}" = "true" ]; then
     echo "Installing default context.xml with substituted environment variables"
     envsubst < "${CONFIG_DIR}"/context.xml > "${CATALINA_HOME}/conf/context.xml"
   fi
+
+  # Use a custom "web.xml" if the user mounted one into the container
+  if [ -d "${CONFIG_OVERRIDES_DIR}" ] && [ -f "${CONFIG_OVERRIDES_DIR}/web.xml" ]; then
+    echo "Installing configuration override for web.xml with substituted environment variables"
+    envsubst < "${CONFIG_OVERRIDES_DIR}"/web.xml > "$CATALINA_HOME/webapps/geoserver/WEB-INF/web.xml"
+  fi
 fi
 
 # start the tomcat