Unable to disable Keycloak springboot adapter

Using Springboot 1.5.9

keycloak.enabled=true

works fine but

keycloak.enabled=false

results in a stack trace...

java.lang.NullPointerException: null
at org.keycloak.adapters.KeycloakDeploymentBuilder.internalBuild(KeycloakDeploymentBuilder.java:55)
at org.keycloak.adapters.KeycloakDeploymentBuilder.build(KeycloakDeploymentBuilder.java:164)
at org.keycloak.adapters.springboot.KeycloakSpringBootConfigResolver.resolve(KeycloakSpringBootConfigResolver.java:37)
at org.keycloak.adapters.AdapterDeploymentContext.resolveDeployment(AdapterDeploymentContext.java:88)
at org.keycloak.adapters.PreAuthActionsHandler.preflightCors(PreAuthActionsHandler.java:107)
at org.keycloak.adapters.PreAuthActionsHandler.handleRequest(PreAuthActionsHandler.java:79)
at org.keycloak.adapters.springsecurity.filter.KeycloakPreAuthActionsFilter.doFilter(KeycloakPreAuthActionsFilter.java:81)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.csrf.CsrfFilter.doFilterInternal(CsrfFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:331)
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)

I think it is related to the following line in org.keycloak.adapters.springboot.KeycloakAutoConfiguration

@ConditionalOnProperty(value = "keycloak.enabled", matchIfMissing = true)

When keycloak.enabled = false then this annotation will cause the bean to not be instantiated which means that a null value is passed resulting, eventually, in the above exception.