diff --git a/public/java/src/org/broadinstitute/sting/gatk/walkers/annotator/HomopolymerRun.java b/public/java/src/org/broadinstitute/sting/gatk/walkers/annotator/HomopolymerRun.java
index 197a00243..7caddac95 100755
--- a/public/java/src/org/broadinstitute/sting/gatk/walkers/annotator/HomopolymerRun.java
+++ b/public/java/src/org/broadinstitute/sting/gatk/walkers/annotator/HomopolymerRun.java
@@ -17,7 +17,7 @@ import java.util.List;
 import java.util.Map;
 
 /**
- * Largest contiguous homopolymer run of the variant allele in either direction on the reference.
+ * Largest contiguous homopolymer run of the variant allele in either direction on the reference.  Computed only for bi-allelic sites.
  */
 public class HomopolymerRun extends InfoFieldAnnotation implements StandardAnnotation {