diff --git a/java/src/org/broadinstitute/sting/gatk/filters/ReadGroupBlackListFilter.java b/java/src/org/broadinstitute/sting/gatk/filters/ReadGroupBlackListFilter.java
index 139df5c05..28102852c 100644
--- a/java/src/org/broadinstitute/sting/gatk/filters/ReadGroupBlackListFilter.java
+++ b/java/src/org/broadinstitute/sting/gatk/filters/ReadGroupBlackListFilter.java
@@ -53,7 +53,7 @@ public class ReadGroupBlackListFilter implements SamRecordFilter {
     }
 
     private void addFilter(Map<String, Collection<String>> filters, String filter, File parentFile, int parentLineNum) {
-        if (filter.toLowerCase().endsWith(".txt")) {
+        if (filter.toLowerCase().endsWith(".list") || filter.toLowerCase().endsWith(".txt")) {
             File file = new File(filter);
             try {
                 int lineNum = 0;