[rules-users] Make Eclipse Drools Builder ignore .csv files

I have an existing Eclipse project that I just converted to a Drools project so that I could get the benefit of automatic compilation of my rule files and decision tables. This worked, but with an unfortunate side effect. My project also contains .csv files that are not Drools decision tables. The Drools Builder flags these files with an error. Can I configure my project so that the Drools Builder will ignore these files? If not, is there a good workaround? The .csv files open nicely in Excel, so I don't want to change the file extension unless I can get the same effect. I am using Drools 5.5.0.Final. Best wishes, Tom