Prefill support not working correctly

The minimum pool size does not match the min-pool-size parameter in the standalone.xml file for my data source. I am setting a min-pool-size of 100, with a max-pool-size of 150, but I actually get 200 connections in the pool. In fact, the actual pool size always seems to be double whatever I set the min-pool-size to. I also have the max-pool-size and prefill parameters set, and it looks as follows:

<pool>
<min-pool-size>
100
</min-pool-size>
<max-pool-size>
150
</max-pool-size>
<prefill>
true
</prefill>
<use-strict-min>
true
</use-strict-min>
</pool>