diff --git a/gatk.wdl b/gatk.wdl
index 3d4bf9231de1cc4259e10ca1c9ba9cebc34ae4e6..1f76099f1d66d8d8c829348f7e8bf94fe386fb22 100644
--- a/gatk.wdl
+++ b/gatk.wdl
@@ -373,7 +373,7 @@ task SplitNCigarReads {
 
     output {
         File bam = outputBam
-        File bamIndex = sub(outputBam, "\\.bam$", ".bai")
+        File bamIndex = sub(outputBam, "\.bam$", ".bai")
     }
 
     runtime {