diff --git a/macs2.wdl b/macs2.wdl
index 999f3f0fdb570289d0614d605741218aebc91984..9803e2f971f1944ccc6a6bdc1f481ae1ecb48b06 100644
--- a/macs2.wdl
+++ b/macs2.wdl
@@ -14,7 +14,7 @@ task peakCalling {
     }
 
     output {
-        File peakFile = outDir + "/" + sampleName + "/macs2/" + sampleName + "_peaks.narrowPeak"
+        File peakFile = outDir + "/" + sampleName + "/macs2/" + sampleName + "_peaks.narrowPeakd"
     }
 
     runtime {