diff --git a/gatk.wdl b/gatk.wdl
index 195627e44b5de984d7d79df93bea926723b1dddc..b5fd4a8d78ab641fd99abf6da0ae1a26f4212c7f 100644
--- a/gatk.wdl
+++ b/gatk.wdl
@@ -279,7 +279,7 @@ task SplitNCigarReads {
 
     output {
         File bam = outputBam
-        File bam_index = sub(outputBam, "\\.bam$", ".bai")
+        File bamIndex = sub(outputBam, "\\.bam$", ".bai")
     }
 
     runtime {