Using custom JVM options files in jvm.options.d/ shows duplicate JVM args

I have a custom.options file in my config/jvm.options.d/ directory with the following contents:

-Xms2g
-Xmx2g

When looking at the running Elasticsearch process, I see that there are two sets of command line parameters for the running process:

-Xms1g -Xms1g ... -Xms2g -Xms2g

Presumably the first set of heap configurations is coming from the default jvm.options file, and the second set is coming from my custom JVM option file. Is this expected behavior? It seems like the second set of configurations is what gets applied, but it is misleading. It can be confusing to figure out which JVM flag is being applied.